This adds a new class, PBEasyPipe, which can do most of the pipe handling
in an easy way.
We use this to call `git rev-parse --git-dir` to find our current git
repository. This means that we can now call GitX within a subdirectory :)
This makes the initial startup much faster. Commits get loaded in a separate
thread, and are displayed every 1000 commits.
There is a bug in here that makes fails a click while it is loading the commit
list. Not sure how to fix this, perhaps send the arrayController?
Pieter de Bie