- AuthLib is loaded only in fhcauth_helper, PermissionLib and REST_Controller

- Removed all the NOT usefull loads of helpers and libraries
- Fixed undefined index in controllers/system/UDF and model system/UDF_model
- APIv1_Controller now loads helper fhcauth
- FHC_Controller now loads ithe fhc and session helpers too
- Added/Fixed comments
- PermissionLib does NOT use anymore the getAuthUID function from the fhcauth helper, now relies on AuthLib directly
- REST_Controller loads directly the AuthLib when is needed

application/libraries/REST_Controller.php

@@ -1814,6 +1814,9 @@ abstract class REST_Controller extends CI_Controller {
             return FALSE;
         }
 
+		// Loads authentication library
+		$this->load->library('AuthLib');
+
         if (is_callable([$auth_library_class, $auth_library_function]) === FALSE)
         {
             $this->load->library($auth_library_class);