Fixing guest code for RH & SUSE

Hi,

I guess there was no time yet to migrate & test the RH code, so here's at least the guest part (haven't tested other parts, but the VM goes up ok).

Additionaly, for SUSE (both openSUSE & SLES) the change_host_name method was always broken it seems, because the location of the permanent host name differs from RedHat.

Regards,
Elad