FIX with `mman.collect()` and partially HIDE 2 remaining erors.

Retrofitted API to use `with ...` resource handling.

chore(rename): gitdb2 v2.0

v2 is chosen to better match the name.

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