Automated host provisioning (WIP)

This fixture is from the 'old' code and has a few problems. Most notable is that it requires the "ks-px.cfg" to be present in the cfme_tests dir. @psav reimplemented some of this when he migrated pxe provisioning over, which can be used as an example:

https://github.com/RedHatQE/cfme_tests/blob/master/cfme/tests/infrastructure/test_pxe_provisioning.py#L60

I think a requirement for porting this code over is that the tests must work without a "ks-px.cfg" in the cfme_tests dir.

Another problem, though less severe, is that this fixture writes to the database, which we would be wise to avoid.