Category finder style cleanups

* Renamed class to CategoryFinder (camel case)
* Removed pointless empty constructor
* Swapped wfProfileIn/Out for ProfileSection
* Renamed scan_next_layer() to scanNextLayer() because underscores
  are ugly (no public callers)
* Made scanNextLayer() and check() private, no callers outside class
* Explicitly made run() and seed() public
* Removed ugly underscores from seed() parameter
* More useful variable name in single caller

Change-Id: Iaffea7634c7b17ed5324b3b5c9b938c1a1348555
Merge "Category finder style cleanups"