Revert "~filsel-minleg"

Screen is probably a better root process than our _urbinit script.

~mirdyr-nislux was helping me test this stuff out, and on his system this version had better results.  On my system, the other version had better results, but in reality screen is probably a better Pid-1 than _urbinit.

There is still yebyen/urbinit:latest with (master) branch, but for how much longer I'm not sure, I was not able to push a tag after I pushed mirdyr-nislux.  I might need to delete the docker index repository yebyen/urbinit and recreate it. https://index.docker.io/u/yebyen/urbinit/