Move some common linux stuff into linuxutil

Signed-off-by: Chris Lalancette <clalancette@gmail.com>
Remove unnecessary bootloader lines in Fedora

Signed-off-by: Chris Lalancette <clalancette@gmail.com>
Add support for Ubuntu 13.04

Signed-off-by: Chris Lalancette <clalancette@gmail.com>
Warn instead of failing when given libvirt_xml with more than one disk

Oz itself never generates libvirt XML with more than one disk.

Allowing users to pass in modified guests at their own risk allows
for some interesting use cases.

The one I'm specifically interested in involves using Image Factory
plus Oz to drive the creation of Live CD images entirely inside of
VMs.
Fixes to improve pylint score

Signed-off-by: Chris Lalancette <clalancette@gmail.com>
Added support for setting custom MAC address to guests

This patch allows the users to specify the MAC address
of the guests instead of using the default generator
included in Oz. This can bring some flexibility while
customizing the guests OS in networks with non-trivial
DHCP configurations.
Add support for Ubuntu 13.04 (Stable release on 25th of April) and add in 12.04.2 (Mid Feb)
Clean up imports and various other smaller items

- Import OzException directly instead of referencing the full package name
- Import various os.path and oz.ozutil functions to more readable and shorter lines
- Replace multiple write() calls with a single multi line write() call