ifcfg/write-ifcfg.sh: bind bond and bridge interfaces to HW

either by s390 SUBCHANNELS or HWADDR, if the interface name is not
persistent.

Previously, this was bound unconditionally with HWADDR.
cms/cmssetup.sh: fixed indention
cms/cmssetup.sh: understand DASD="none"

Treat DASD="none" as unset.

https://bugzilla.redhat.com/show_bug.cgi?id=1096979
qemu: install virtio_console kernel module

https://bugzilla.redhat.com/show_bug.cgi?id=1097999
dracut-functions.sh: exit for missing  --force-add or --add dracut modules

Better exit with fail early, so there is no surprise on reboot.
do 'ip route replace default' instead of 'add'

When you define the gateway for an interface, dracut sets it up with:

  ip route add default via $gw dev $netif

If a default route is already set (e.g. if you have multiple NICs), this
will fail with the message "RTNETLINK answers: File exists".

So, if your first NIC isn't usable as a default route

Using "ip route replace default" instead allows ifup/dhclient-script to
correctly change the default route to the new interface.