Transaction inputs are now prepopulated with empty scriptSig. Each signer
is expected to update this scriptSig with a signature at a proper place.
There is a new method in RedeemData to locate index of the key/signature
within scriptSig/program.
To generalize an above approach for all supported types of inputs,
RedeemData can now represent data for any type of input. For
pay-to-address and pay-to-pubkey inputs it is expected to contain single
key and CHECKSIG program.
Signers now accept ProposedTransaction object that could carry additional
metadata shared between signers. For now it shares derivation path of the
signing key.
To preserve the dummy sig feature, a new flag was introduced in a SendRequest.
It specifies whether to fill empty sigs with dummies during tx completion
or not. Default value is true (for backward compatibility).
There is a CustomTransactionSigner class that may be used as a base for
simple third-party signers (or may be not). It is used in unit test which
may be treated as a usage example.
So that these keys are stored in the same order they appear in redeem script. That would make easier for signers to locate signature position in scriptSig.
In the end the API evolved in such a way that changing this param isn't that useful. To do contracts you tend to work with transactions directly, and a Wallet subclass that needs to do special signing by default can override the signing engine used.
Introduced pluggable signers notion. Instances of
TransactionSigner could be added into the wallet, so that they subsequently
applied to transaction to complete it.
Existing signing code (Transaction.signInputs) was refactored into
LocalTransactionSigner, which is always implicitly added to any wallet.
Related pull request: #157
* A constructor that only takes the wallet as an argument
* A setTransactionBroadcaster() which should be called when the Bitcoin network is ready
Motivation: Some wallets (MultiBitHD) does not use WalletAppKit, and starts with reading the wallet before initializing the bitcoin network.
Now these wallets can create the wallet (and the wallet file is read), and call the setter after the bitcoin network is up.
We were not previously triggering lookahead before calculating a Bloom filter, which means we might have missed transactions in some edge cases. Add a test to catch this and then fix up various unit tests to have fewer magic numbers and be more robust to changes.
