Search by Property Category

* Update search logic in listing controller
* Add room category to fields to forms
* Update search results controller
* The room category commit should be swapped with this commit
https://trello.com/c/F9jyfw3A
@houndci You can't be the only pet in the family; we care about `cat`, even if it is unused.

/cc @hrs @nnarh @CharlesMassry