GUAC-932: null connection group identifier does NOT mean root. This is implementation-dependent.
GUAC-932: Update connection location upon save.
GUAC-932: Migrate to generic service for object retrieval. Add parent update (move) to group service.
GUAC-932: Add support for modifying connection/group/user permissions within PermissionSet.
GUAC-932: Update user connection/group permissions when saved.