Pyflakes

- Do not report undefined name for generator expression and dict or
set comprehension at class level.
- Deprecate ``Checker.pushFunctionScope`` and ``Checker.pushClassScope``:
use ``Checker.pushScope`` instead.
- Remove dependency on Unittest2 for the tests.

- Fix computation of ``DoctestSyntaxError.lineno`` and ``col``.
- Add boolean attribute ``Checker.withDoctest`` to ignore doctests.
- If environment variable ``PYFLAKES_NODOCTEST`` is set, skip doctests.
- Environment variable ``PYFLAKES_BUILTINS`` accepts a comma-separated
list of additional built-in names.

- File ``bin/pyflakes`` was missing in tarball generated with distribute.
- Fix reporting errors in non-ASCII filenames (Python 2.x).

- Add --version and --help options.
- Support ``python -m pyflakes`` (Python 2.7 and Python 3.x).
- Add attribute ``Message.col`` to report column offset.
- Do not report redefinition of variable for a variable used in a list
comprehension in a conditional.
- Do not report redefinition of variable for generator expressions and
set or dict comprehensions.
- Do not report undefined name when the code is protected with a
``NameError`` exception handler.
- Do not report redefinition of variable when unassigning a module imported
for its side-effect.
- Support special locals like ``__tracebackhide__`` for py.test.
- Support checking doctests.
- Fix issue with Turkish locale where ``'i'.upper() == 'i'`` in Python 2.

- Fix detection of variables in augmented assignments.

- Support Python 3 up to 3.3, based on the pyflakes3k project.
- Preserve compatibility with Python 2.5 and all recent versions of Python.
- Support custom reporters in addition to the default Reporter.
- Allow function redefinition for modern property construction via
property.setter/deleter.
- Fix spurious redefinition warnings in conditionals.
- Do not report undefined name in ``__all__`` if import * is used.
- Add WindowsError as a known built-in name on all platforms.
- Support specifying additional built-ins in the ``Checker`` constructor.
- Don't issue Unused Variable warning when using locals() in current scope.
- Handle problems with the encoding of source files.
- Remove dependency on Twisted for the tests.
- Support ``python setup.py test`` and ``python setup.py develop``.
- Create script using setuptools ``entry_points`` to support all platforms,
including Windows.