Remove xmlutils module

The xmlutils module is being removed from oslo-incubator as it's not
useful anymore. Various fixes have been integrated into the base XML
module provided by Python now.

See
http://lists.openstack.org/pipermail/openstack-dev/2014-September/047368.html
for details.

Change-Id: Iefa1a5a4d08a3cfc43b3c9764fc2d35c328a19e3
Merge "Remove xmlutils module"