[Pkg-libvirt-maintainers] Bug#901940: Updated the merge request

[Christian Ehrhardt]

Hi,
looking ahead in preparation to post-buster being more open for such
changes I updated the merge request. Is is rebased to match latest git
and further has:
- adapted the dropping of xen.so
- added a news file as requested
- separated qemu.so as well as requested
- made qemu a depends and lxc a recommends as requested

I have not yet opened any bugs with the consuming packages as I wanted
to hear your current feedback on that last update first.