Removes the need to include libgit2 as this is now handled by the
git-utils module which provides functions that were previously in
git.mm and git.coffee
The latest release does not work because of CoffeeScript
changes so use a simple compile script to convert CSON
files to JSON files when buildilng.
Closes#348
npm was noticing the atom.gyp file and trying to do stuff with it
automatically, and moving it out of the way ruins gyp's day. This fixes
both problems.