Deal with request's urllib3 being annoying about 'strict'

These changes are required to get tests to pass in python3.4 (and
presumably others).

This is entirely code from @sashahart, who had done the work earlier
to deal with with some Debian related issues uncovered by @thomasgoirand.

These changes will probably mean the debian packages will need to be
updated when the next version is released.
Ensure PATH_INFO is escaped per PEP-333 implications

Fixes #27 which has a few more details on why PATH_INFO should be
unquoted before being set in the environment.

When doing so, though, we _must_ set either REQUEST_URI or RAW_URI in
the environ to make it possible to construct URIs that have had their
%2Fs trashed. From reading various post-wsgi documents REQUEST_URI is
most common, but some servers, such as gunicorn use RAW_URI, so since
its cheap, we use both here.

Thanks to @Vultaire for the bug report.
Correctly set wsgi.url_scheme when using https

Fixes #26. Thanks to @Vultaire for the patch.

When a HTTPSConnection is used, make sure the faked socket is aware so
the environ can be properly set.