Add settings for brute force prevention
Block user on too many failed logins within specific period
Add cuke for brute force prevention; also add timecop
Add missing migration for brute force prevention
Add user helper for formatting user status

This thing is a bit ugly.
Add user helper for creating lock/unlock/unblock buttons
User/edit: Add buttons for changing user status incl. unblocking

Conflicts:
	app/controllers/users_controller.rb
	features/step_definitions/user_steps.rb