Support removing of groups from a group via REST

A group can be removed from a group by DELETE on
'/groups/*/groups/<group>'.

In addition multiple groups can be removed from a group by
POST on '/groups/*/groups.delete'.

This is consistent with how members can be removed from a group.

The WebUI was adapted to use the new REST API for removing groups
from a group.

Change-Id: I924611b6c413b65d666166758b7d446b782379c7
Signed-off-by: Edwin Kempin <edwin.kempin@sap.com>
4 files changed