Sync my set of ports into the repo.

This collects a bunch of changes, alas.

Signed-off-by: Daniel Pittman <daniel@rimspace.net>
Remove `lang/luajit` since it was merged upstream...
Added Racket port, based on MZ-Scheme

I wanted to try out racket, and wasn't motivated by their binary installers,
so gave this a shot...

Signed-off-by: Daniel Pittman <daniel@rimspace.net>
Remove the racket portfile

Signed-off-by: Daniel Pittman <daniel@rimspace.net>