Bump go-dockerclient.
A few minor Go style suggestions.
Merge pull request #250 from plietar/master

Bump go-dockerclient.
Supporting graceful signal shutdown.

Adding a signal handler and gracefully shutting down all threads.
Merge pull request #251 from vmarmol/shutdown

Supporting graceful signal shutdown.
Also handle SIGTERM.
Merge pull request #253 from vmarmol/shutdown

Also handle SIGTERM.
Fix name resolution in Systemd systems
Undo changes to if statements as requested by vmarmol. Fix typos in my changes.
Undo changed to Errorf in manager.go re: capatalization.
And a few more capatalization undos.
More if undos.
And yet another if.
Fix assignment error in haste.
Updating libcontainer dependency.
Merge pull request #255 from vishh/update_deps

Updating libcontainer dependency.
A few minor Go style suggestions.
Undo changes to if statements as requested by vmarmol. Fix typos in my changes.
Undo changed to Errorf in manager.go re: capatalization.
And a few more capatalization undos.