updates validateaddress to match the changes
in bitcoind https://github.com/bitcoin/bitcoin/pull/10583.
removes the fields ismine and iswatchonly, those
are things that a wallet would know, not a node.
adds segwit related fields, witness_version and
witness_program. test changes to the node rpc method
validateaddress with p2pkh, p2sh, p2wpkh and p2wsh addresses