adds a remove method
Merge branch 'develop' of https://github.com/dirkschumacher/iUPB into develop

Conflicts:
	app/controllers/ads_controller.rb
	app/models/ad.rb
adds a time ago for posts and minor change in ads controller
changes search param to "q" from "search" - it's cleaner :)
enhances the index view
creates an edit view and enhances the show view of ads
Merge branch 'develop' of https://github.com/dirkschumacher/iUPB into develop

Conflicts:
	app/views/ads/_search_field.html.erb
	app/views/ads/index.html.erb
	app/views/ads/show.html.erb