Update site.py

fix a bugs in 'system.describe'
Fix #7, support experimental the py3k
Update site.py
Update site.py
Update site.py
use current_app json encoder instead of flask.json
Merge pull request #10 from nside/master

use current_app json encoder instead of flask.json
Merge pull request #9 from jordanfung/master

Sorry for the delay.

Web Browsable was finalizing the API #3.

Thank you so much!
Addings web browsable API
Merge with #9
Merge with #3
Fix tests #3