correct the bugs reference url in man documents

All the bugs reference in nova man documents are incorrect.
Nova bugs are managed at launchpad, not the nova.openstack.org

Change-Id: Id5bbf09ad8ba079d4de959314123437031ded3ab
Instance groups: validate policy configuration

Ensure that API does not allow conflicting policies to be configured
on an instance group. More specifically the user should not be allowed
to configured 'anti-affinity' and 'affinity' on the same instance group.

In addition to this a validation will also be done on the policy, that is,
if the policy is not supported then an exception will be raised.

This is part of blueprint instance-group-api-extension.

Change-Id: Id19c55cb60109819429f73e2b28efe7f15cc5194
Merge "Instance groups: validate policy configuration"
Merge "correct the bugs reference url in man documents"