Note: there is no user interface for editing the owners list.
It is supposed to be done through the API (to be done)

Not activated by default

Removed South and related files

AnObj sharing and permission at Backend level
AnObjMgr in FrontEnd allow editing of the sharing
properties. Is able to liste shared AnObj

Functions for Thumbnail creation and borders are 
now in adim_app.utils

Thumbnail creation and border are called at view
level from adim_app (no more in models)

Thumbnail size in settings, no more hardcoded