Select transaction inputs, based on data from bitcoind
Added initial, untested transaction signing code
Added ctypes-based interface to crypto-functionality in OpenSSL
Added creation of signatures
Added signature checking
Implemented script deserialization; finished transaction signing (still not completely tested, and for now it's signed with the wrong keys in the test script)
Start of using private key from bitcoind for signatures
Added SHA256 and RIPEMD160 to crypto.py and implemented base58 encoding
Implemented Base58 decoding