Make the settings parameter optional for the renderer constructors.

This changes the order of parameters for WebRenderer. The constructor tries to detect the old usage to avoid breaking backward compatibility and logs a warning.
Moved the demo to http://arnavion.github.io/libjass/demo/index.xhtml
Fixed AMD check to also test for `define.amd`
Parse color and alpha values more loosely; correct tests accordingly

Fixes #28
tsnext