Bug 997848 - Inherited capabilities not in REST API

With the changes to use CapabilityProxy, the default API serialization (Rails) was serializing the user's underlying attribute from Mongoid, not the proxy overlay of inherited capabilities.  Changed to use serializable_hash which uses the proper values
Merge pull request #3435 from smarterclayton/bug_997848_capabilities_not_shown_via_api

Merged by openshift-bot