Create method to disable slideshow

[ryndel]

For various reason, you may want to disable the slideshow - for a particular screen width, old browser etc.
Create a method to disable slideshow: example code:
slideshow = null;
var $el = $("#slideshow");
$el.unbind();
$el.removeClass("ui-slideshow");
$el.find(".slide").removeClass("ui-slideshow-slide");
// remove inline styles
$el.find(".wrapper").removeAttr("style");
$el.find(".slide").removeAttr("style");