Prior to this commit, the sendtomany.py script
would sometimes fail based on the output of the
RPC call gettxout returning only a script, and not
an address. After this commit, the validation will
still work correctly in these cases using the
chosen cryptoengine to convert from script to address.
Also notably, the return value of utxo set does
not include an 'address' key any more.
Tests are updated to reflect this.