Features/search

@effkay /cc @ryabrody 

fulltext search. Ready to be reviewed and merged.

* pg search with LIKE fallback
* Postgres fulltext search
* Search form/result templates (overridable)
* Searchable pages
* Weighted search attributes (not configurable)
  1. title
  2. keywords
  3. description and fulltext all bricks)

TODOs:
* migrate to postgres (more specific testing possible)