Add switch that shuts RiffRaff down when it is inactive
Tweaks to timing and messages
Improvements from Phil's feedback

 - Extract disable deployment from the switch
 - Introduce postCleanup event so we are not guessing when we can shutdown
Merge pull request #186 from guardian/sh-shutdown-when-inactive

Add switch that shuts RiffRaff down when it is inactive
Fix up switch logic for deploysEnabled
Add self deployment to webapp types
Clean up expression of URL call