Bump go-dockerclient.
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.
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.
More if undos.
And yet another if.
Fix assignment error in haste.
Merge branch 'master' of github.com:satnam6502/cadvisor

Conflicts:
	manager/manager.go