refactor agent support into common
AGENT_DEFAULT should be -1
envoyd: refactor connection handling
standardize on -t,--agent=
add more status messages
refactor some code
move to an event based loop
epoll_fd should have EPOLL_CLOEXEC set
stderr doesn't need to be flushed
just hard code def_socket_path
add GPL message to common.c
envoy can now request which agent to start

Buggy, but it works.
envoyd: timeout should be -1... ಠ_ಠ
envoy: got the first run logic wrong
cleanup envoy
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
envoyd: send the agent type across the socket
simplify the default agent logic
code cleanups
should be checking type everywhere