importlib2

Hi all,

Motivated at PyCon by the "pymigrate" discussions, I started
backporting importlib to 2.7.  I've finally freed up some time in the
last week or so and have come close to having the project ready to
release on the cheeseshop (as importlib2).  I'm hosting the repo and
bug tracker on bitbucket:

https://bitbucket.org/ericsnowcurrently/importlib2

Feel free to take it for a spin.  Keep in mind that any functionality
that depends on the no-longer-implicit import state (finders/path
hooks) will not work without first calling importlib2.hook.inject().
That includes importlib2.import_module().  If you notice any other
rough corners just let me know.

There are a few minor things I want to wrap up before officially
releasing the project, but that shouldn't take much work.  In parallel
I'm going to start working on the pymigrate* project, which will
leverage importlib2 and importers to facilitate per-module enforcement
of the 2.7/3.x intersection language.

Lastly, I can never offer enough thanks to Brett Cannon for importlib
and its thorough test suite.  It's made the backporting job possible
(and almost easy).  Thanks Brett!

-eric

* Go go gadget bikeshed!