sshpeer: implement peer for version 2 of wire protocol Since the protocol is now negotiated before we construct a peer instance, we can return the negotiated protocol from the handshake function and instantiate an appropriate peer class for the protocol. Version 2 of the SSH protocol is currently identical to version 1 post handshake. So our sshv2peer class just inherits from sshv1peer for the time being. This will obviously change over time. Differential Revision: https://phab.mercurial-scm.org/D2063