Major update

Thanks a lot for your work. I had to modify this for a client and I wanted to share this with you guys.

 * Added easing and complete arguments (as Zepto and jQuery).
 * Some comments added.
 * Better restoration of elemets when sliding is completed.
 * Returns the Zepto collection.
 * GruntJS setup and task configration

I also renamed the file, I hope you don't mind.