Switch incategory to simple matching.

incategory is no longer a search like other searches - it now only
ignores case and accents.  Otherwise, you have to specify the category
exactly.  This prevented the problem where you would search for a
category like "movie" and get stuff in the "movie production techniques"
category.

Bug: 53415
Change-Id: Ib03fc923af8d8b8f4e4a0bc0f71fa3592f309fe9
Merge "Switch incategory to simple matching."