eliminate explicit specification of protocol in tests and
loops over protocol. We only support SSHv2 now.
Upstream-Regress-ID: 0082838a9b8a382b7ee9cbf0c1b9db727784fadd
[regress/cipher-speed.sh regress/forcecommand.sh regress/forwarding.sh]
Sync regress tests to -current; include dtucker@'s new cfgmatch and
forcecommand tests. Add cipher-speed.sh test (not linked in yet)