Upgraded examples from python-oauth to python-oauth2

[jace]

I've upgraded example/server.py and example/client.py to use oauth2 instead of oauth. Running the server and then the client executes a sample transaction between the two.

[kmccarthy]

Thanks you!!!

[imxiaobo]

Is it merged?

[jace]

Not yet merged, but it's not a particularly useful example. Both server and client make HTTP requests with full URLs (including http:// and the domain) which should only be done with a proxy server. The pair will effectively only work with each other.