A series of backwards compatible with Minerva changes that will
allow us to throw away the rlModuleLoader without considerable bytes
added on the critical path.

* categoryOverlay is moved into mobile.startup. It makes use of the
promisedView to access CategoryTabs. This makes clicking the category
button in AMC synchronous.
* mobile.category.overlay module now exposes CategoryTabs and CategoryAddOverlay
in a single object.
* rlModuleLoader and the old defines for accessing Categories are marked as
deprecated

Change-Id: I5774603deef2ff76ff5ff7d1f97b2e511b126deb
Bug: T214641