this is following a SUSE model for tests where we need a server
end but don't want setting up the server to constitute a real
test in itself, we want it to be stable. The 'support_server'
test just boots a pre-built (by createhdds) disk image, sets up
networking, and runs the iSCSI server.
To run the iSCSI test we need to handle networking config in
anaconda (or we would need to set the support server up as a
DHCP server, which may be worth considering), so this adds that.
We also need to be able to specify the target device for a
volume in custom partitioning, so this adds that too.