Ensure maintenance mode is only run on rails-app layers.
Merge branch 'master' into staging

Conflicts:
	deploy/recipes/maintenance.rb
Added treadmill worker support.
Merge branch 'master' into staging
Fixed missing attributes file for tread_mill
Updated tread_mill scripts.
Added tread_mill upstart support.
Fixed provider to user upstart.
Remove log redirect (fails to run)