🚨 Important change to TTY direct start mode

[joske]

To be able to support running yserver via lightdm, and concurrently directly on the TTY, I had to deprecate the libseat/logind code. So if you start from TTY directly, you again HAVE to be in input and video groups (or equivalently have access to /dev/dri/xx and /dev/input/xxx).

So now you can start as many yservers as you like 😁

This is effective from cb9fe3b.