Create class Authentication

 - Add fields for the class Authentication
 - Add a constructor
Add methods for control class fields

 - Add method setPerms
 - Add method getPerms
 - Add method getToken
Add signals and slots for authentication

 - Add signal loadAuthUrl
 - Add slot beginAuth
 - Add slot login
Add signals and slots for answers

 - Add signal authError
 - Add signal authFinished
 - Add slot frobReceived
 - Add slot tokenReceived