Fix crash when ALLOW_MAKE_JOBS is set

Reported by:	gjb
Exclude /portdistfiles when running mtree
When detecting stage orphans, don't exclude anything.

This fixes finding /var/run/PORTNAME as an orphan.
Trivial merge + css tweaks

Apparently fossil can't do split commits after a merge, and I forgot to
commit the css tweaks earlier.
Double space allocation for /var to 200M

The port textproc/dixit needs 109M to install its database.
I suspect the port should be using /usr/local/var for something that
big, but that's a different discussion I guess.