Allow Nova Quotas to be Disabled
Allow Nova Quotas to be Disabled

This allows some of the nova quotas to be set to -1, disabling that
quota.

Closes-Bug: #1610332

Change-Id: I499b52b8a327307ad79cca112e43b50f1f3ea482

cloudbase/nova,mahak/nova,openstack/nova,mikalstill/nova,rajalokan/nova,openstack/nova,Juniper/nova,mikalstill/nova,klmitch/nova,klmitch/nova,rahulunair/nova,mikalstill/nova,klmitch/nova,cloudbase/nova,jianghuaw/nova,cloudbase/nova,hanlind/nova,openstack/nova,rahulunair/nova,vmturbo/nova,Juniper/nova,alaski/nova,mahak/nova,vmturbo/nova,phenoxim/nova,sebrandon1/nova,jianghuaw/nova,rajalokan/nova,vmturbo/nova,rahulunair/nova,rajalokan/nova,sebrandon1/nova,gooddata/openstack-nova,vmturbo/nova,mahak/nova,sebrandon1/nova,gooddata/openstack-nova,jianghuaw/nova,rajalokan/nova,klmitch/nova,gooddata/openstack-nova,gooddata/openstack-nova,Juniper/nova,hanlind/nova,hanlind/nova,alaski/nova,Juniper/nova,phenoxim/nova,jianghuaw/nova