import via LinkedIn #346
Merge remote-tracking branch 'origin/develop' into linkedin

Conflicts:
	app/views/students/_form_old.html.erb
	config/routes.rb
	db/seeds.rb
Merge remote-tracking branch 'origin/develop' into linkedin

Conflicts:
	Gemfile.lock
fixed some namings in linked in controller
transferred auth method of linkedin_controller to student_controller #346
transferred linked in client to new structure for name, email, status and linked in link.
Merge remote-tracking branch 'origin/develop' into linkedin

Conflicts:
	app/controllers/students_controller.rb
fixed test
simplified update_attributes
added ProgrammingLanguages import functionality #362
removed unnecessary files #362
Adding flash notification #362
Merge pull request #362 from hpi-swt2/linkedin

Linkedin
restricting access rights for deactivated students and employers/staff
Merge branch 'develop' into feature/activation

Conflicts:
	app/controllers/students_controller.rb
	app/models/ability.rb
	app/views/students/_profile_fields.html.erb