Encapsulate dependencies on ActionController (refactoring)

**As a** developer 
**In order to** make dependencies transparent 
**And** to make the code testable in spite of them (see #104)
**I want** all dependencies to be properly encapsulated 
**And** I want them to be injected in the methods that use them 

The dependencies on Devise and ActiveRecord are under control, lets continue with the code which depends on ActionController.