Avoid loading revisions for every search result

The core SearchResult implementations are insane. initFromTitle()
loads revisions for every single search result. The only place
Cirrus still relies on this is isMissingRevision(). Since we know
we're reasonably up to date, let's assume revisions are never
missing.

Change-Id: I85ef144376f6ec078b34bfb36fb28888002e7522
Merge "Avoid loading revisions for every search result"