User is deactivated instead of deleted
User can activate itself by visiting panel, wich is equal to login action
Only active users are participating in Lecture
Only admin can see inactive users
Fix list ui for activate/deactivate user
User needs to have profile to activate itself
Only admin can see user email
Merge branch 'sptq_develop' into develop

Conflicts:
	app/controllers/users_controller.rb
Merge pull request #60 from vircung/develop

Accounts cant be deleted