Support 'x-www-form-urlencoded' content type.

Always return http status code '200 OK'. (Unlesss server internal error 5xx)
And including failure reason in http body with json format.
Compare hash case insensitive.
Add shard counter (by googler, Brett Slatkin)

See: https://cloud.google.com/appengine/articles/sharding_counters
Add client library for google visualization api.

See project: https://code.google.com/p/google-visualization-python/
version 1.8.2.
This is helper library to generate data used by google visualization
api.
Add google visualization javascript api.

This is for IDE editor to do code auot-complete.
Fine tune content block in template file.
Add test chart.
Reorganize module structure and add dispatch file.