catalog js-gui tweaks

* force server ordering to be respected on refresh, so new default versions show at root
* update applications as well as entities
* fix bug where sometimes on relead, policies would cause errors in browser
allow region and endpoint specified as explicit keys to override ones set implicitly
don't cause NPE inside location list coercions (alt fix for recent fix for NPE from where this is invoked in MachineLifecycleTasks), and some notes on jclouds location for softlayer
catch disappearing definitions of sensors/config between rebinds/version changes, and better error logging then also
Persistence fix for removing and adding same ID catalog item

If a catalog item with the same ID is removed and then added back the delta persister will first update the stored item and then delete it, regardless of the initial order of removal-addition. This may result in the catalog items disappearing from store even though they were just added.

Explicitly remove catalog item with same ID from the removed set if new object is added.
better comments for config key and better coercion tests (code review of previous commits)
This closes #333
This closes #334