mkvtoolnix: help find ogg/vorbis

Closes #28761.
pari: use gmp

Closes #29072.
ffmpeg: set GIT_DIR so head builds can determine the version

Fixes #29118.
boot2docker 0.9.0

Closes #29117.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
hashpump: 1.0.2 (new formula)

Closes #28443.
Allow disabling arch flag filtering
llvm: build universal under superenv