Heavily modified lilyterm config.

Too much changes to remember.
Minor changes to .i3/config. Also changed wallpaper.

Lilyterm is now started in single process mode. This seems to fix a bug
where it steals focus. I don't even.
expandtab is now default. Adds scheme.vim.
Defaults MPD_HOST to mpd.rzl.

I'm at the RaumZeitLabor way too much.