Removed dedicated models for computing and user conf, and merged it in the models themselves. Added support for the groups. Minor fixes and improvements.

Added the power user status and restricted options for standard users when adding containers and running taks. Fixed bug in proxy auth.

Refactored the computing type by adding the access mode. Refactored the computing manager classes. Added the "access_mode" field and related sys and user conf in the Computing model.

Added the manager and conf properties to the Computing class. Global computing conf refactoring. Minor fixes.