1. "Safe" mode -- from Py2 to modern Py2 or Py3 to more-compatible Py3

   • Split the fixers into two categories: safe and bold

   • Safe is highly unlikely to break existing Py2 or Py3 support. The output of this still requires :mod:`future` imports. Examples:

     • Compatible metaclass syntax on Py3
     • Explicit inheritance from object on Py3

   • Bold might make assumptions about which strings on Py2 should be unicode strings and which should be bytestrings.

     • We should also build up a database of which standard library interfaces on Py2 and Py3 accept unicode strings versus byte-strings, which have changed, and which haven't.

2. Windows support

• [Done] Add more tests for bytes ... preferably all from test_bytes.py in Py3.3.
• [Done] Add remove_hooks() and install_hooks() as functions in the :mod:`future.standard_library` module. (See the uprefix module for how to do this.)

Experimental: - Add:

from future import bytes_literals
from future import new_metaclass_syntax
from future import new_style_classes

• [Done] Maybe:

  from future.builtins import str
  

  should import a custom str is a Py3 str-like object which inherits from unicode and removes the decode() method and has any other Py3-like behaviours (possibly stricter casting?)