changes to represent validity of p2sh addresses as master protocol addresses
Added language on handling ClassBs where the sender is a p2sh address.  OP_CHECKMULTISIG only supports public keys.  No public key hashes or script hashes are allowed.  As such the canonical Senders Address is the 1 of N necessary to redeem the output is not available to p2sh addresses.  As it was never explicitly required in the spec that this pubkey match the senders address, it is now explicitly mentioned that it can be any address the sender designates to be the output redeemer
Merge pull request #246 from wanderingbort/p2sh-support

P2sh support