Added options to narrow notification scope and improve performance.
* New "-o/--only-affected" option
* New "--status" option

Will now filter out instances from all_servers based on ip filter
(static NeCTAR zone-ip mapping also added). Will also only gather info
for the affected tenants when zone is specified.

Change-Id: I4ed08a940a9210197d6d0a6ae197878926d828ca
Merge "Added options to narrow notification scope and improve performance. * New "-o/--only-affected" option * New "--status" option"