Adding casualjs

Description: A HTML5 Canvas Framework (ActionScript3.0 like)
Source: https://code.google.com/p/casualjs/
License: Apache License 2.0
Author: seems to be Alex Li. The email listed on Google code was for
flashlizi. I followed the link to the blog listed on Google code and in
the “About Me” section, there was a flashlizi (Alex Li) listed.
http://www.riaidea.com/blog/about