Option to rename toggle event, don't depend on '$' being jQuery

In attempting to use this widget, I ran into a couple of snags.  Our javascript dependencies are a bit complex, and the trigger('toggle') was getting intercepted by some prototype code, so I added on option to give it a name.

Also, the jQuery '$' isn't available everywhere, so I renamed some of the references to jQuery.  Probably better to use the jQuery conventions of passing in the jQuery reference and binding it locally to $, but this was simpler.