Completely overhauled the plugin

Hi Stéphane!

I was searching for this exact functionality for one of my current projects and found your great plugin. I overhauled it to be JSHint perfect and without any unused code, etc. etc.

You should really add a real license to your plugin. My personal recommendation would be the [AGPLv3](http://www.gnu.org/licenses/agpl.html) or a [Creative Commons](http://creativecommons.org/) one. You should also delete any code from other people from your repository. The stuff you've written in your `README` is no license and practically nobody is allowed to use your plugin right now (and I'm currently violating your copyright with this pull request).

Last but not least, consider registering your plugin in the [bower](https://github.com/bower/bower) registry.

What else? Well, I'd rename the repository and plugin to `jQuery.scrollSections` to comply with all other plugins out there in the world.

Kindest regards
Richard