Added RHEL 6.4
Allow the user to specify disk bus and nic model

Signed-off-by: Chris Lalancette <clalancette@gmail.com>
Fix up Mandrake 8.2 breakage from last commit

Signed-off-by: Chris Lalancette <clalancette@gmail.com>
Remove unused variables and imports pointed out by pyflakes

Signed-off-by: Chris Lalancette <clalancette@gmail.com>
Update Ubuntu unittests to handle new support

Signed-off-by: Chris Lalancette <clalancette@gmail.com>