Added Ubuntu to mk_kvm types

Note that kickstart files for CentOS changed from 'c' to 'centos'
Unattended Ubuntu install working

Configures hostname from kernel boot, not via
the recommend re-run of netcfg.
Handles empty and partitioned disks
Limits LVM use to 10G leave freespace in VG
Installs from network mirror, not locally.
Local mirror install fails as per this thread:
https://lists.fedorahosted.org/pipermail/cobbler/2012-November/008399.html