Expire cached blocks using a sweeper_helper on all sweepers
Merge branch 'ai2657' of git://github.com/caioformiga/noosfero-ecosol into cirandas

Conflicts:
	app/helpers/sweeper_helper.rb
	app/sweepers/article_sweeper.rb
	app/sweepers/profile_sweeper.rb
	app/sweepers/role_assignment_sweeper.rb