4 Addresses failures when cleaning up orphaned openstack ports.
5 The main "openstack <object> list" command no longer accepts
6 the "-c created_at" option, which has been moved to a property
7 of the object and must now be queried with "openstack show object
8 UUID". Also, the created_at parameter sometimes returns "None"
9 instead of a timestamp, and the existing version of the script
10 does not catch this condition.