Make sure the default initrd_system is set to dracut
for the vmx image type and to kiwi if no initrd_system
is specified. This allows to simplify other code parts
as we can trust there is a value set
Updates all XML descriptions to latest schema version and
also includes adaptions to the test XML descriptions for
testing the new Xen guest and server setup
Some attributes needed to be changed in the test xmls. With this
commit all the description files are consistent with the new co-
occurrence constraints.
At the moment there is no class to build the pxe client config
file from information provided with the optional pxedeploy
section. However this is not fatal to the build because the file
could be created manually too. Thus a warning message is shown
which will go away when the pxe client config file creation
has been ported
