Update README.md
Update README.md
New module named lithium.extras.js. Move Li.move and Li.contains there.
Also added Li.compact (which help remove undefined properties from an
object).
Made Li.forEach chainable.
Observable: Removed Li.observable and the ability to make arbitrary
objects into publishers. Now one must inherit Li.Observable to make a
class/function a publisher.
Lithium 0.3.0. Check Changelog.txt.