Merge pull request #5 from harley-que/master

merged authenticate and authorize into one authenticate with authorizing...
Change double quotes to single quotes for more consistent style. Change the status code from 404 to 401 for unauthroized requests.
supplement readme.md
Merge pull request #6 from luodandan/master

supplement readme.md
Fixed bug of client/upstream.py chekipip() getting wrong ip addr in NAT environment, GET /ip remain the same problem
fix bug of deletesilo
Added support for mac