A group can be included into a group by PUT on
'/groups/*/groups/<group>'. The request also succeeds if the group is
already included.
In addition multiple groups can be included into a group by POST on
'/groups/*/groups/' or '/groups/*/groups.add'.
This is consistent with how new members can be added to a group.
This new REST API is not yet used from the WebUI since the
GroupInfoCache which is used there needs to be adapted first. This will
be done in a follow-up change.
Change-Id: Iecc365b341f09eea1ced16757192065fe3b28a21
Signed-off-by: Edwin Kempin <edwin.kempin@sap.com>
b78e9e3afd