As taken from https://github.com/gitpython-developers/gitdb/blob/master/gitdb/stream.py#L292
->
NOTE: Behavior changed in PY2.7 onward, which requires special handling to make the tests work properly.
They are thorough, and I assume it is truly working.
Why is this logic as convoluted as it is ? Please look at the table in
https://github.com/gitpython-developers/gitdb/issues/19 to learn about the test-results.
Bascially, on py2.6, you want to use branch 1, whereas on all other python version, the second branch
will be the one that works.
However, the zlib VERSIONs as well as the platform check is used to further match the entries in the
table in the github issue. This is it ... it was the only way I could make this work everywhere.
IT's CERTAINLY GOING TO BITE US IN THE FUTURE ... .
<-

Fixes #19

autopep8 -v -j 8 --max-line-length 120 --in-place --recursive

It's a nice way of saying that there is still one failing, consistently.

Conflicts:
	gitdb/base.py
	gitdb/fun.py
	gitdb/pack.py
	gitdb/stream.py
	gitdb/test/lib.py
	gitdb/util.py

This makes it easier to deal with things internally as now
everything is passed as bytes.

There were a few things which were being reused consistently for
compatibility purposes, such as the `buffer`/`memoryview` functions
as well as the `izip` method which needed to be aliased for
Python 3.  The `buffer` function was taken from `smmap` [1] and
reworked slightly to handle the optional third parameter.

This also adds a compatibility file dedicated entirely to encoding
issues, which seem to be the biggest problem.  The main functions
were taken in part from the Django project [2] and rewritten
slightly because our needs are a bit more narrow.

A constants file has been added to consistently handle the
constants which are required for the gitdb project in the core
and the tests.  This is part of a greater plan to reorganize
the `util.py` file included in this project.

This points the async extension back at the original repository
and points it to the latest commit.

[1]: https://github.com/Byron/smmap/blob/1af4b42a2354acbb53c7956d647655922658fd80/smmap/util.py#L20-L26
[2]: https://github.com/django/django/blob/b8d255071ead897cf68120cd2fae7c91326ca2cc/django/utils/encoding.py