Re-enable Search and Several Beta-Blocking Fixes

Code Review: http://mrccodereview.cloudapp.net/ui#review:id=1123
Deployment: cz-july2013-javierluraschi-fixes.azurewebsites.net

Scenarios:
- Can't search items in ChronoZoom.
- Can't save timelines nor exhibits anymore.

Causes:
- We simplified our schema to use GUIDs (not unique IDs) and modified APIs to match REST APIs. However, changes in the client were not performed.
- New User API implementation was missing to handle annonymous users.

Fixes:
- Change REST API to align to lower-casing convention. Change client to search by GUID for timeline, exhibit, content item.
- Centralize user-collections-permissions logic and fix issue for anonymous user.

Bugs Resolved: https://github.com/alterm4nn/ChronoZoom/issues/85