signrawtransaction  [{"txid":txid,"vout":n,"scriptPubKey":hex},...] [,...] [sighashtype="ALL"]
Sign inputs for raw transaction (serialized, hex-encoded).
Second optional argument (may be null) is an array of previous transaction outputs that
this transaction depends on but may not yet be in the blockchain.
Third optional argument (may be null) is an array of base58-encoded private
keys that, if given, will be the only keys used to sign the transaction.
Fourth optional argument is a string that is one of six values; ALL, NONE, SINGLE or
Returns json object with keys:
hex : raw transaction with signature(s) (hex-encoded string)
complete : 1 if transaction has a complete set of signature (0 if not)
Don't trust. Verify. Docs extracted from src/rpcrawtransaction.cpp#L294-L309.