Enable / disable auto slideshow

Hi Brad,

we are already using the slideshow at www.terrafinanz.de. Because of our big images, we will only start autosliding after all images are loaded.

I added the functionality to enable auto sliding later and to disable auto sliding.

Can you please accept my pull request?

Here is my Code for enabling autosliding:
$( window ).load(function(){ 
	$( "#stage" ).data( "Swipe" ).auto(4000);
});

We have a separate control bar and hovering the control bar, we will stop auto sliding.
$( "#stage-control" ).on( "mouseenter", function() {
         $( "#stage" ).data( "Swipe" ).auto(0);
} );

Thank you very much and greetings from munich, germany, sebastian