Add bower.json

Bower allows easy installation of front-end dependencies. By adding a
`bower.json`, your package is easier to discover and to install, because the
`main` property can provide a hint of where to find the main file of your
project.

You can install RGBaster with `bower install rgbaster`.
updated cors demo
added license to readme
Merge branch 'bower' of https://github.com/passy/rgbaster.js into passy-bower
fixes #1 - updated readme with version, license, and notes
added in keywords
not trying to be too strict, but...