Initial checkin of BitCoinJ

TODO

@@ -0,0 +1,23 @@
+Here is a brief list of things that still need to be done.
+
+More unit tests:
+   - Implement more unit tests for block chain functionality
+   - Create a MockNetworkConnection and use it to test the Peer.
+
+Protocol:
+   - Properly support multiple chains
+   - Start up faster
+      - Store a block locator in the wallet
+      - Parse the stored headers at startup, then download the rest
+   - Provide a seed node list in the NetworkParameters.
+   - Implement tx fees.
+   - Support import of private keys and then extracting its transactions from the block chain.
+   - Longer term potentially add a getmerklebranch protocol command so we can check 0-confirmation transactions.
+
+Examples/documentation:
+   - Implement a simple Swing GUI payment app.
+
+Cleanup:
+   - Find a way to avoid some horrid hacks when shutting down the network connection.
+   - Implement a BitCoin class that encapsulates a BigInteger and formatting.
+   - Make NetworkParameters use subclasses instead of static methods to construct.