Extract EE specific files/lines for app/controllers

We have the following files containing EE specific code. We should move them to ee/

• app/controllers/application_controller.rb
• app/controllers/autocomplete_controller.rb
• app/controllers/dashboard_controller.rb
• app/controllers/ldap/omniauth_callbacks_controller.rb (Use an EE module to wrap other EE modules)
• app/controllers/omniauth_callbacks_controller.rb
• app/controllers/projects_controller.rb