Update to newest vcap_common gem
Fix bug where staging kills CC when app disappers
Added a catch all for Fatal Server Exceptions.

- We need to put this through something like airbrake but for now our syslog aggregator emails should work
use dea.shutdown to invalidate advertisements

this solves the homer simpson problem of evacuating an app to the same
DEA it was on

[finishes #50233251]
Add ServiceInstance's dashboard_url to the app_summary endpoint
unregister routes when shutting down

[finishes #50333517]
[Finishes #49790341] if an offering has no public plans, the service should not be visible to public users
Refactor stager_pool
Clean up dea_pool
More pool cleanup
[fixes #50333517] Unpublish routes eventually gives up if NATS isn't responding in 2s