add support for weixin, each upload is now also uploaded to weixin. So
that an official weixin account can serve as a bot to respond certain
messages with current picture. Only the client side implementation is
part of the commit.
forgot to remove old upload code import
Better handling of WX exceptions, API exceptions.
add WX upload limiting API call support
Add/fix code documentation for WX
fix readme link
add GPL notice to WX class
put api call limit into config.py
Merge pull request #6 from paulshi/master

Weixin Upload with Rate Limiting