Added an Immediately Invoked Function Expression to make sure that $ was...

... an alias for jQuery when this library is used in contexts where the global $ might have been changed.

I'm working on a legacy project that has both Prototype and jQuery. ColReorder was blowing up because the global $ was last set by Prototype. I wrapped the main function with a locally defined $ to get around the problem and thought the change might be useful to others stuck in the same boat