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
User index: show status and allow filtering by status
User index: show blocked and locked users under "permenently locked"
User edit: Remove change status link
Add spec and cukes
User index: add links for changing user status
Add cuke for changing user status from index page
Prevent users from changing their own status
Allow disabling brute force prevention
Don't show notice about brute force prevention when it's disabled
Fix users helper spec
Fix forced password change cuke
Fix authentication with external auth source
UsersController: Fix test for sending mail on user activation