Gesundheit in the browser

Queries and nodes now support a to/from JSON interface allowing them to be
compiled to a datastructure on the client.
Basic marshal/unmarshal architecture with pluggable validator
Add try-in-your-browser to docs
Cleaning up old files in doc/
Document new client-side support
rename bundle.js to gesundheit-standalone.js
remove Makefile in favor of 'scripts' in package.json
update standalone bundle (new browserify)
0.9.0