xmonad: make k0's layouts simpler
xmonad: make k0's layouts simpler

k0 currently uses two widescreen monitors both in portrait orientation,
so the new `layoutNoMirror` layout works better.

We also remove some cruft, like ewmh (I use UIM, not SCIM) and the
trailing vim-specific comment.

listx/syscfg,listx/syscfg,listx/syscfg,listx/syscfg,listx/syscfg