[api-ref]Add notification for server group operations

[OpenStack Infra]

https://review.openstack.org/107954
commit daf278c0c8b6cc917b84f514fec65758adf17028
Author: Jay Lau <email address hidden>
Date: Thu Oct 16 15:08:32 2014 -0400

    Add notification for server group operations

    Currently, there is no notification when create/update/delete
    server groups, this caused some 3rd party client cannot know
    when those operations are finished.

    The fix was adding notifications for those operations.

    DocImpact
    The wiki page https://wiki.openstack.org/wiki/SystemUsageData
    needs to be updated once this patch was merged.

    Change-Id: Ia1f4a6752668ddb73ebb8faf525b58a28d183754
    Closes-Bug: #1343200

[Anne Gentle (annegentle)]

I'd like this information to be automated rather than updated in a wiki page. Confirming the bug for tracking purposes.

[Markus Zoeller (markus_z) (mzoeller)]

This is an automated cleanup. This bug report has been closed because it
is older than 18 months and there is no open code change to fix this.
After this time it is unlikely that the circumstances which lead to
the observed issue can be reproduced.

If you can reproduce the bug, please:
* reopen the bug report (set to status "New")
* AND add the detailed steps to reproduce the issue (if applicable)
* AND leave a comment "CONFIRMED FOR: <RELEASE_NAME>"
  Only still supported release names are valid (LIBERTY, MITAKA, OCATA, NEWTON).
  Valid example: CONFIRMED FOR: LIBERTY