Add updated contracts, reorganize contract file structure

packages/contracts/contracts/Exchange.sol

@@ -16,11 +16,11 @@
 
 */
 
-pragma solidity 0.4.11;
+pragma solidity ^0.4.11;
 
 import "./TokenTransferProxy.sol";
-import "./base/Token.sol";
-import "./base/SafeMath.sol";
+import "./tokens/Token.sol";
+import "./lib/SafeMath.sol";
 
 /// @title Exchange - Facilitates exchange of ERC20 tokens.
 /// @author Amir Bandeali - <amir@0xProject.com>, Will Warren - <will@0xProject.com>

packages/contracts/contracts/TokenRegistry.sol

@@ -16,9 +16,9 @@
 
 */
 
-pragma solidity 0.4.11;
+pragma solidity ^0.4.11;
 
-import "./base/Ownable.sol";
+import "./lib/Ownable.sol";
 
 /// @title Token Registry - Stores metadata associated with ERC20 tokens. See ERC22 https://github.com/ethereum/EIPs/issues/22
 /// @author Amir Bandeali - <amir@0xProject.com>, Will Warren - <will@0xProject.com>

packages/contracts/contracts/TokenTransferProxy.sol

@@ -16,10 +16,10 @@
 
 */
 
-pragma solidity 0.4.11;
+pragma solidity ^0.4.11;
 
-import "./base/Token.sol";
-import "./base/Ownable.sol";
+import "./tokens/Token.sol";
+import "./lib/Ownable.sol";
 
 /// @title TokenTransferProxy - Transfers tokens on behalf of contracts that have been approved via decentralized governance.
 /// @author Amir Bandeali - <amir@0xProject.com>, Will Warren - <will@0xProject.com>

packages/contracts/contracts/base/Ownable.sol

@@ -1,27 +0,0 @@
-pragma solidity 0.4.11;
-
-/*
- * Ownable
- *
- * Base contract with an owner.
- * Provides onlyOwner modifier, which prevents function from running if it is called by anyone other than the owner.
- */
-
-contract Ownable {
-    address public owner;
-
-    function Ownable() {
-        owner = msg.sender;
-    }
-
-    modifier onlyOwner() {
-        require(msg.sender == owner);
-        _;
-    }
-
-    function transferOwnership(address newOwner) onlyOwner {
-        if (newOwner != address(0)) {
-            owner = newOwner;
-        }
-    }
-}

packages/contracts/contracts/base/SafeMath.sol

@@ -1,41 +0,0 @@
-pragma solidity 0.4.11;
-
-contract SafeMath {
-    function safeMul(uint a, uint b) internal constant returns (uint256) {
-        uint c = a * b;
-        assert(a == 0 || c / a == b);
-        return c;
-    }
-
-    function safeDiv(uint a, uint b) internal constant returns (uint256) {
-        uint c = a / b;
-        return c;
-    }
-
-    function safeSub(uint a, uint b) internal constant returns (uint256) {
-        assert(b <= a);
-        return a - b;
-    }
-
-    function safeAdd(uint a, uint b) internal constant returns (uint256) {
-        uint c = a + b;
-        assert(c >= a);
-        return c;
-    }
-
-    function max64(uint64 a, uint64 b) internal constant returns (uint64) {
-        return a >= b ? a : b;
-    }
-
-    function min64(uint64 a, uint64 b) internal constant returns (uint64) {
-        return a < b ? a : b;
-    }
-
-    function max256(uint256 a, uint256 b) internal constant returns (uint256) {
-        return a >= b ? a : b;
-    }
-
-    function min256(uint256 a, uint256 b) internal constant returns (uint256) {
-        return a < b ? a : b;
-    }
-}

packages/contracts/contracts/multisig/MultiSigWallet.sol

@@ -1,4 +1,4 @@
-pragma solidity 0.4.11;
+pragma solidity ^0.4.11;
 
 /// @title Multisignature wallet - Allows multiple parties to agree on transactions before execution.
 /// @author Stefan George - <stefan.george@consensys.net>

packages/contracts/contracts/multisig/MultiSigWalletWithTimeLock.sol

@@ -16,9 +16,9 @@
 
 */
 
-pragma solidity 0.4.11;
+pragma solidity ^0.4.11;
 
-import "./base/MultiSigWallet.sol";
+import "./MultiSigWallet.sol";
 
 /// @title Multisignature wallet with time lock- Allows multiple parties to execute a transaction after a time lock has passed.
 /// @author Amir Bandeali - <amir@0xProject.com>

packages/contracts/contracts/multisig/MultiSigWalletWithTimeLockExceptRemoveAuthorizedAddress.sol

@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity 0.4.11;
+pragma solidity ^0.4.11;
 
 import "./MultiSigWalletWithTimeLock.sol";
 

packages/contracts/contracts/test/DummyToken.sol

@@ -1,7 +1,7 @@
-pragma solidity 0.4.11;
+pragma solidity ^0.4.11;
 
 import "./Mintable.sol";
-import "./../base/Ownable.sol";
+import "./../lib/Ownable.sol";
 
 contract DummyToken is Mintable, Ownable {
     string public name;
@@ -21,7 +21,9 @@ contract DummyToken is Mintable, Ownable {
         balances[msg.sender] = _totalSupply;
     }
 
-    function setBalance(address _target, uint _value) onlyOwner {
+    function setBalance(address _target, uint _value)
+        onlyOwner 
+    {
         uint currBalance = balanceOf(_target);
         if (_value < currBalance) {
             totalSupply = safeSub(totalSupply, safeSub(currBalance, _value));

packages/contracts/contracts/test/DummyToken_v2.sol

@@ -0,0 +1,37 @@
+pragma solidity 0.4.18;
+
+import "./Mintable_v2.sol";
+import "./../lib/Ownable_v2.sol";
+
+contract DummyToken_v2 is Mintable_v2, Ownable_v2 {
+    string public name;
+    string public symbol;
+    uint public decimals;
+
+    function DummyToken(
+        string _name,
+        string _symbol,
+        uint _decimals,
+        uint _totalSupply)
+        public
+    {
+        name = _name;
+        symbol = _symbol;
+        decimals = _decimals;
+        totalSupply = _totalSupply;
+        balances[msg.sender] = _totalSupply;
+    }
+
+    function setBalance(address _target, uint _value) 
+        public
+        onlyOwner 
+    {
+        uint currBalance = balanceOf(_target);
+        if (_value < currBalance) {
+            totalSupply = safeSub(totalSupply, safeSub(currBalance, _value));
+        } else {
+            totalSupply = safeAdd(totalSupply, safeSub(_value, currBalance));
+        }
+        balances[_target] = _value;
+    }
+}

packages/contracts/contracts/test/MaliciousToken.sol

@@ -1,11 +1,13 @@
-pragma solidity 0.4.11;
+pragma solidity ^0.4.11;
 
-import "./../base/StandardToken.sol";
+import "./../tokens/StandardToken.sol";
 
 contract MaliciousToken is StandardToken {
     uint8 stateToUpdate = 1;  // Not null so that change only requires 5000 gas
 
-    function updateState() internal {
+    function updateState() 
+        internal 
+    {
         stateToUpdate++;
     }
 

packages/contracts/contracts/test/Mintable.sol

@@ -1,14 +1,16 @@
-pragma solidity 0.4.11;
+pragma solidity ^0.4.11;
 
-import "./../tokens/ERC20Token.sol";
-import "./../base/SafeMath.sol";
+import "./../tokens/UnlimitedAllowanceToken.sol";
+import "./../lib/SafeMath.sol";
 
 /*
  * Mintable
  * Base contract that creates a mintable UnlimitedAllowanceToken
  */
-contract Mintable is ERC20Token, SafeMath {
-    function mint(uint _value) {
+contract Mintable is UnlimitedAllowanceToken, SafeMath {
+    function mint(uint _value) 
+        public
+    {
         require(_value <= 100000000000000000000);
         balances[msg.sender] = safeAdd(_value, balances[msg.sender]);
         totalSupply = safeAdd(totalSupply, _value);

packages/contracts/contracts/test/Mintable_v2.sol

@@ -0,0 +1,18 @@
+pragma solidity 0.4.18;
+
+import "./../tokens/ERC20Token.sol";
+import "./../lib/SafeMath_v2.sol";
+
+/*
+ * Mintable
+ * Base contract that creates a mintable UnlimitedAllowanceToken
+ */
+contract Mintable_v2 is ERC20Token, SafeMath_v2 {
+    function mint(uint _value) 
+        public
+    {
+        require(_value <= 100000000000000000000);
+        balances[msg.sender] = safeAdd(_value, balances[msg.sender]);
+        totalSupply = safeAdd(totalSupply, _value);
+    }
+}

packages/contracts/contracts/tokens/ERC20Token.sol

@@ -1,12 +1,15 @@
-pragma solidity 0.4.11;
+pragma solidity ^0.4.18;
 
-import "./../base/Token.sol";
+import "./Token_v2.sol";
 
-contract ERC20Token is Token {
+contract ERC20Token is Token_v2 {
 
     uint constant MAX_UINT = 2**256 - 1;
 
-    function transfer(address _to, uint _value) returns (bool) {
+    function transfer(address _to, uint _value)
+        public
+        returns (bool) 
+    {
         require(balances[msg.sender] >= _value && balances[_to] + _value >= balances[_to]); 
         balances[msg.sender] -= _value;
         balances[_to] += _value;
@@ -19,7 +22,10 @@ contract ERC20Token is Token {
     /// @param _to Address to transfer to.
     /// @param _value Amount to transfer.
     /// @return Success of transfer.
-    function transferFrom(address _from, address _to, uint _value) returns (bool) {
+    function transferFrom(address _from, address _to, uint _value)
+        public 
+        returns (bool) 
+    {
         uint allowance = allowed[_from][msg.sender];
         require(balances[_from] >= _value && allowance >= _value && balances[_to] + _value >= balances[_to]); 
         balances[_to] += _value;
@@ -31,17 +37,28 @@ contract ERC20Token is Token {
         return true;
     }
 
-    function balanceOf(address _owner) constant returns (uint) {
-        return balances[_owner];
-    }
-
-    function approve(address _spender, uint _value) returns (bool) {
+    function approve(address _spender, uint _value) 
+        public
+        returns (bool)
+    {
         allowed[msg.sender][_spender] = _value;
         Approval(msg.sender, _spender, _value);
         return true;
     }
 
-    function allowance(address _owner, address _spender) constant returns (uint) {
+    function balanceOf(address _owner)
+        public
+        view
+        returns (uint)
+    {
+        return balances[_owner];
+    }
+
+    function allowance(address _owner, address _spender) 
+        public
+        view
+        returns (uint)
+    {
         return allowed[_owner][_spender];
     }
 

packages/contracts/contracts/tokens/EtherToken.sol

@@ -16,10 +16,10 @@
 
 */
 
-pragma solidity 0.4.11;
+pragma solidity ^0.4.11;
 
-import "./../tokens/UnlimitedAllowanceToken.sol";
-import "./../base/SafeMath.sol";
+import ".//UnlimitedAllowanceToken.sol";
+import "./../lib/SafeMath.sol";
 
 contract EtherToken is UnlimitedAllowanceToken, SafeMath {
 

packages/contracts/contracts/tokens/EtherToken_v2.sol

@@ -16,12 +16,12 @@
 
 */
 
-pragma solidity 0.4.11;
+pragma solidity 0.4.18;
 
-import "./../tokens/ERC20Token.sol";
-import "./../base/SafeMath.sol";
+import "./ERC20Token.sol";
+import "./../lib/SafeMath_v2.sol";
 
-contract EtherToken_v2 is ERC20Token, SafeMath {
+contract EtherToken_v2 is ERC20Token, SafeMath_v2 {
 
     string constant public name = "Ether Token";
     string constant public symbol = "WETH";

packages/contracts/contracts/tokens/StandardToken.sol

@@ -1,4 +1,4 @@
-pragma solidity 0.4.11;
+pragma solidity ^0.4.11;
 
 import "./Token.sol";
 

packages/contracts/contracts/tokens/Token.sol

@@ -1,4 +1,4 @@
-pragma solidity 0.4.11;
+pragma solidity ^0.4.11;
 
 contract Token {
 
@@ -35,4 +35,4 @@ contract Token {
 
     event Transfer(address indexed _from, address indexed _to, uint _value);
     event Approval(address indexed _owner, address indexed _spender, uint _value);
-}
+}

packages/contracts/contracts/tokens/Token_v2.sol

@@ -0,0 +1,38 @@
+pragma solidity 0.4.18;
+
+contract Token_v2 {
+
+    /// @return total amount of tokens
+    function totalSupply() public view returns (uint) {}
+
+    /// @notice send `_value` token to `_to` from `msg.sender`
+    /// @param _to The address of the recipient
+    /// @param _value The amount of token to be transferred
+    /// @return Whether the transfer was successful or not
+    function transfer(address _to, uint _value) public returns (bool) {}
+
+    /// @notice send `_value` token to `_to` from `_from` on the condition it is approved by `_from`
+    /// @param _from The address of the sender
+    /// @param _to The address of the recipient
+    /// @param _value The amount of token to be transferred
+    /// @return Whether the transfer was successful or not
+    function transferFrom(address _from, address _to, uint _value) public returns (bool) {}
+
+    /// @notice `msg.sender` approves `_addr` to spend `_value` tokens
+    /// @param _spender The address of the account able to transfer the tokens
+    /// @param _value The amount of wei to be approved for transfer
+    /// @return Whether the approval was successful or not
+    function approve(address _spender, uint _value) public returns (bool) {}
+
+    /// @param _owner The address from which the balance will be retrieved
+    /// @return The balance
+    function balanceOf(address _owner) public view returns (uint) {}
+
+    /// @param _owner The address of the account owning tokens
+    /// @param _spender The address of the account able to transfer the tokens
+    /// @return Amount of remaining tokens allowed to spent
+    function allowance(address _owner, address _spender) public view returns (uint) {}
+
+    event Transfer(address indexed _from, address indexed _to, uint _value);
+    event Approval(address indexed _owner, address indexed _spender, uint _value);
+}

packages/contracts/contracts/tokens/UnlimitedAllowanceToken.sol

@@ -16,9 +16,9 @@
 
 */
 
-pragma solidity 0.4.11;
+pragma solidity ^0.4.11;
 
-import "./../base/StandardToken.sol";
+import "./StandardToken.sol";
 
 contract UnlimitedAllowanceToken is StandardToken {
 

packages/contracts/contracts/tokens/ZRXToken.sol

@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity 0.4.11;
+pragma solidity ^0.4.11;
 
 import "./UnlimitedAllowanceToken.sol";
 

packages/contracts/package.json

@@ -44,7 +44,7 @@
     "dirty-chai": "^2.0.1",
     "mocha": "^4.0.1",
     "solc": "^0.4.18",
-    "truffle": "3.4.3",
+    "truffle": "^4.0.1",
     "tslint": "5.8.0",
     "types-bn": "^0.0.1",
     "types-ethereumjs-util": "0xProject/types-ethereumjs-util",

packages/contracts/test/ts/erc20Token.ts

@@ -9,7 +9,7 @@ import {ContractInstance} from '../../util/types';
 
 import {chaiSetup} from './utils/chai_setup';
 
-const {DummyToken} = new Artifacts(artifacts);
+const {DummyTokenV2} = new Artifacts(artifacts);
 const web3: Web3 = (global as any).web3;
 chaiSetup.configure();
 const expect = chai.expect;
@@ -24,7 +24,7 @@ contract('ERC20Token', (accounts: string[]) => {
     let token: ContractInstance;
 
     beforeEach(async () => {
-        token = await DummyToken.new({from: owner});
+        token = await DummyTokenV2.new({from: owner});
         await token.mint(MAX_MINT_VALUE, {from: owner});
         tokenAddress = token.address;
     });
@@ -33,7 +33,7 @@ contract('ERC20Token', (accounts: string[]) => {
         it('should throw if owner has insufficient balance', async () => {
             const ownerBalance = await zeroEx.token.getBalanceAsync(tokenAddress, owner);
             const amountToTransfer = ownerBalance.plus(1);
-            return expect(token.transfer.call(owner, spender, amountToTransfer, {from: spender}))
+            return expect(token.transfer.call(spender, amountToTransfer, {from: owner}))
                 .to.be.rejectedWith(constants.REVERT);
         });
 

packages/contracts/test/ts/exchange/core.ts

@@ -610,7 +610,7 @@ contract('Exchange', (accounts: string[]) => {
             });
 
             return expect(exWrapper.fillOrderAsync(order, taker, {shouldThrowOnInsufficientBalanceOrAllowance: false}))
-                .to.be.rejectedWith(constants.INVALID_OPCODE);
+                .to.be.rejectedWith(constants.REVERT);
         });
 
         it('should not change balances if an order is expired', async () => {

packages/contracts/util/artifacts.ts

@@ -6,6 +6,7 @@ export class Artifacts {
     public Exchange: any;
     public ZRXToken: any;
     public DummyToken: any;
+    public DummyTokenV2: any;
     public EtherToken: any;
     public EtherTokenV2: any;
     public MultiSigWalletWithTimeLockExceptRemoveAuthorizedAddress: any;
@@ -18,6 +19,7 @@ export class Artifacts {
         this.Exchange = artifacts.require('Exchange');
         this.ZRXToken = artifacts.require('ZRXToken');
         this.DummyToken = artifacts.require('DummyToken');
+        this.DummyTokenV2 = artifacts.require('DummyToken_v2');
         this.EtherToken = artifacts.require('EtherToken');
         this.EtherTokenV2 = artifacts.require('EtherToken_v2');
         this.MultiSigWalletWithTimeLockExceptRemoveAuthorizedAddress = artifacts.require(