Display URL and label for ttp shared objects

DRF:
	Updated permission check for Annotation (compatibility with v3.*) using PermissionClass
	Added a TTPAuthentication class (adim_ttp.authentication.TTPAuthentication) so api call can be done without user token

AnObj Manager:
	Updated the properties panel for TTP shared object: the link for editing the object in the distant service is more visible

Conflicts:
	.gitignore
FIXED

If a user is created without a uniqueId, but the value of the attribute is given later, it is
added to the user. This address the case when a user is shibbolized afterwards.

The TTP permission classes are bulit from settings, no need for hardcoding.

TSD ...

Wrong conditional testing in ImgMgr

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