This module manager border colors for the windows and handles
automatically maintaining the colors across stack changes.

This also adds green borders to pinned windows to differentiate them
from normal windows.

This reverts commit 87b103a4995fd2b6bbd1e72c446fd789caf5a050.

A pinned window will always try to stay on the same screen in the sname
position if it can.

Each screen now has its own history and if a workspace is swapped with
another visible workspace, the history between those screens is also
swapped, so this gives a feeling of a kind of persistent history that
follows the screen.

This is achieved by using `stack build --ghc-options=-ddump-minimal-imports`
and looking for the *.imports files.