Fixes an issue that could cause pack access to hang while iterating t…

…hrough pack objects ...

fix smmap related issues

fixes python 3 issue on windows

fixes gitpython-developers/GitPython#220

Merge branch 'py2n3'

* python 3 compatibility
* all tests work in py2.6, 2.7, 3.3, 3.4

bumped version to 0.5.4

removed test suite from being distributed. It didn't work properly an…

…yway and I am not going to dig into the setup tools mess

Added zip_safe flag to setup.py

Adjusted setup.py to deal more gracefully with build failures of our …

…optional extensions

Added fixes to setup.py to allow easy_installation