Feature #1742: Add a set of group IDs to Users
Feature #1742: Methods to add and remove secondary groups
Feature #1742: List resources from secondary groups
Feature #1742: add/del secondary group requires MANAGE GROUP
Feature #1742: When a user is deleted, it is now removed from the secondary groups
Feature #1742: chgrp does not delete the user from the previous group

This allows users to use the chgrp to change their own primary
group to one of the secondary ones
Feature #1742: Add migrator to 4.3.80
Feature #1742: Add secondary groups to the CLI
Feature #1742: secondary groups actions in Java OCA
Feature #1742: Add secondary groups to fsck
Feature #1742: Update user pool xsd
feature #1742: Redo parsers, clear set of group ids in case of failed authN
Merge branch 'feature-1742'