Bug/dollars browser jquery

Hello,
*JQuery.$.browser()* has been deprecated since jQuery 1.3 and is removed in 1.9. So to test with JQuery 2.0, I deleted this function and updated *js/libs/ui/gumby.skiplink.js*.

You can test Gumby with JQuery 2.0 on :

 * http://gumby.caouecs.fr/index.html (for demo.html)
 * http://gumby.caouecs.fr/ui.html