Improve support for APIURLs without scheme or netloc

UseContext.decorate_url_with_authentication(url) now can provide a default scheme and netloc if those parts aren't provided an APIURL input parameter.

Add support for Py2.7 with python-future lib

Used python-future lib (http://python-future.org/index.html) to add support for Py2.7.

Patch release to add API route string validation

1.1.1

Validate API route chars, and include py3.4 as supported

Minor release to add new method for tokenizing a full URL

Added D2LUserContext.decorate_url_with_authentication() to accept an entire URL and generate Valence authentication tokens for it; re-factor D2LUserContext to pull out the token generation code into an internal method (_build_tokens_for_path()).