Update Pin Maps for the B+

So I originally used this API on a B and it worked great. Now I moved to using a B+, and none of the additional GPIO pins (29-40) are supported. This seems like a fairly simple fix based on what I can see in the source, but I'm not quite sure what's going on in the version control part. I would be willing to write the fix, but I'd need some guidance on how the versions are handled.

Thanks
