Make compatible with Django Dev (1.7+)

`get_path_info` was moved from `django.core.handlers.base` to `django.core.handlers.wsgi` in commit 636860f.  See https://github.com/django/django/commit/636860f

Here is a sample patch that illustrates the move, suggests a backwards compatible change.  It may not be the cleanest way to do this, but it illustrates the change required.