Cleans up a bunch of unused variables in XenAPI.
Cleans up a bunch of unused variables in XenAPI.

Also fixes a bug in XenAPI where xml.parsers.expat was not
imported, but was being used to catch an exception.

Change-Id: Idfb3b94317ecc13210fa221396c6f2dc10be3ac9

n0ano/ganttclient