Api Authentication

api/login - login with username or mail and password
api/logout - logout

api/auth/createKey - creates an API-Key
api/auth/login - login with username or mail and api-key
api/auth/logout - logout
Clean Up

Move UserService::GetByIdentifier to UserRepository::findByIdentifier

Remove old and unused Files

Remove UserService form Login-Logic
(due to ACL)
Merge pull request #149 from pmattmann/zf2.api.login

Api Authentication