jQuery/themeroller extensions updated

[Pablo]

All extensions using jQuery/themeroller have been updated, because http://www.themeroller.com is now http://jqueryui.com/themeroller/
Also the ThemeSwitcher extension no longer uses the images from the jQuery website, because they've disabled hot linking;(

You can download/install the updated extensions through the Extension Manager (Menu->Tools->Extension Manager->Available Updates).