Add wait for resource deletion on volume teardown

The teardown routines in some of the tests were not
waiting for verification that the volume was actually deleted.
As a result it's easy to intermittently hit a case where we run
out of space for volume create in the following tests.

This patch just adds a resource_deletion check/wait after
each volume delete operation to make sure we don't get ahead
of ourselves.

Change-Id: I47f9ad2b8e6f79348c3d6188da3c24af0c6fe5d4
Fixes: bug 1092689
Fix list images xml deserialization.

Partially fixes bug 1059568

Change-Id: I17f88ca89e089e1f4dc85f785e60f1e08b9f5b39
Merge "Add wait for resource deletion on volume teardown"
Merge "Fix list images xml deserialization."