use virtio devices
exception class name typo fix
More os type options, using virtio as device bus for linux guests
removed unused constant
separated os and architecture, win uses sata, migration
windows xp uses ide instead of sata
windosxp identifier changed
fixed bug wich use_ide_disk apllied to ssytem oepratives with assigned bus
delete old 2.2 migration code
better changelog
better windows separation between current and older

that way we include all modern server versions (2003, 2008...) to use also SATA disks
fixed random ordering on selectors

and change again labels for the windows options

a couple of checks have been also removed with the refactoring
but they were no needed as the methods were invoked only internally
with a controlled set of valid parameters
Merge branch 'jag/virt-virtio'