Change LockTime in TxRawDecodeResult to uint32.
Added MarshalJSON to Vin and changed Vout.ScriptPubKey

Added MarshalJSON method to Vin which properly omits the Vout field
from coinbase Vin's by using anonymous structs with the proper
subsets of fields outputted by bitcoind

Changed Vout.ScriptPubKey to add omitempty for ReqSigs and Addresses:
both fields are not shown when there is an error identifying to
scriptType or parsing addresses in bitcoind
Gofmt.
Export new function ConvertCreateRawTxParams.

The inputs to the createrawtransaction command are JSON strings, however
the NewCreateRawTransactionCmd function takes concrete types.  Thus,
callers which deal with the raw JSON need a method to perform the
validation and conversion.  This logic is the same as what needs to happen
when unmashalling a full JSON-RPC command, so this commit factors that
logic out into a separate function and exports it.
Update coverage report.