batch panic decoding for MacOS

batch panic decoding for MacOS

add support for decoding (nominally) any panic for MacOS. Limited testing.
Requires hdutil from http://www.dementia.org/~shadow/dmgutil-0.1.tar.gz
to extract files from DMGs.

now with support for cross-version debugging, when run on 10.6 (e.g. with kextutil)
Change-Id: I5d9db005e3014e22f916070f8af25271a28615ea
Reviewed-on: http://gerrit.openafs.org/1125
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>