have envoy also wrap ssh directly

If argv[0] = ssh, have envoy grab the environmental variables from
envoyd and invoke ssh directly.

Makes for a convenient wrapper around ssh and avoids a lot of the
pitfalls with gpg-agent.
envoy: fix array copying logic in exec_ssh
envoy: we never need to setenv GPG_AGENT_INFO
Merge branch 'master' into devel

* master:
  envoy: we never need to setenv GPG_AGENT_INFO
  envoy: fix array copying logic in exec_ssh
  have envoy also wrap ssh directly

Conflicts:
	envoy.c