Fixes DOS issue in instance list ip filter

Converts the ip filtering to filter the list locally based
on the network info cache instead of making an extremely expensive
call over to nova network where it attempts to retrieve a list
of every instance in the system.

Change-Id: I455f6ab4acdecacc5152b11a183027f933dc4475
Closes-bug: #1358583
Merge "Fixes DOS issue in instance list ip filter"