Remove parallel indexing of packfiles (#265)
Remove parallel indexing of packfiles (#265)

This is causing "no procs" errors on 9front, but isn't giving
much performance gains, so for now call the callback on each
index in sequence.This is causing "no procs" errors on 9front, but isn't giving
much performance gains, so for now call the callback on each
index in sequence.

driusan/dgit,driusan/dgit