Update rendering.js

Comment edition to solve https://github.com/lmccart/p5.js/issues/299
Merge pull request #300 from ajspadial/master

Update rendering.js
saving pointer to context2d for speed
Merge branch 'master' of github.com:lmccart/p5.js
fixing long line
package num
examples and p5.sound
license
docs for env
Update README.md
version
Merge branch 'master' of github.com:lmccart/p5.js
p5.sound update, adding yuidoc sound assets
merging upstream changes