I broke test_mixin2to3 somehow; distutils2-default is okay and packaging too,
so I don?t see an obvious reason right now, I?ll investigate later.

This does not mean that we can run tests successfully with a Python 2.7
built from its repository: The version that will become 2.7.3 reports
itself as 2.7.2 (except for a ?+? in sys.version, but that?s an
implementation detail).  Some tests need access to Python.h and that
isn?t found when running from an uninstalled Python anyway.

This codebase is compatible with 3.1, 3.2 and 3.3.  It was converted with 2to3
and a semi-automated diff/merge with packaging in 3.3 to fix some idioms.
We?ve now come full circle from 2.x to 3.x to 2.x to 3.x again :)

Starting from now, contributors can make patches for packaging (preferred, as
the stdlib?s regrtest is very useful), distutils2 or distutils-python3, and
we?ll make patches flow between versions.

Backports:
- sysconfig is now always imported from our backports
- when hashlib is not found, our backport is used instead of the md5
  module (debatable; we could just drop hashlib)

Version-dependent features:
- PEP 370 features are only enabled for 2.6+
- the check for sys.dont_write_bytecode was fixed to use getattr
  with a default value instead of hasattr

Idioms/syntax:
- octal literals lost their extra 0
- misused try/except blocks have been changed back to try/finally
  (it?s legal in 2.4 too, it?s only try/except/finally that isn?t)
- exception catching uses the regular 2.x idiom instead of sys.exc_info
- file objects are closed within finally blocks (this causes much
  whitespace changes but actually makes diff with packaging easier)

Renamed modules:
- some missed renamings (_thread, Queue, isAlive, urllib.urlsplit, etc.)
  were fixed

Other:
- a few false positive replacements of ?packaging? by ?distutils2? in
  comments or docstrings were reverted
- util.is_packaging regained its name
- assorted whitespace/comment/import changes to match packaging