Base search layer classes.
Merge branch 'master' into search_layer

Conflicts:
	app/controllers/root_controller.rb
Query method in search layer.
SearchLayer moved into models.
Search layer in models.
Merge branch 'master' into search_layer

Conflicts:
	app/controllers/root_controller.rb
	config/routes.rb
Category filter for announces.
Simple search layer.
Fix search by tag.
Merge pull request #52 from b17/search_layer

Search layer