Basic functionality should be working for incoming calls:
* Fux Intercom to 1337
* Fonial to the Hamburg number
* EPVPN
Still to do: clean up internal extensions and more extensive testing
This groups the files and templates for each host together and therefore
makes it easier to see all the (config) files for a host.
Also clean up incorrect, unused docker_compose config for mumble and
clean up unused engelsystem configs.
