Tabs: Alternative based on collapsibleset

@uGoMobi: @arschmitz:

I know you are sticking with UI tabs, but I still wanted to contribute my latest version of collapsible tabs, which is down to a single option in JS, class and respective CSS. I like it because it's easy to extend and I can fallback to a regular collapsible-set on small screens. Plus it saves a widget :-)

Demo [here](http://www.franckreich.de/jqm/tabview/demo.html)

It's still raw, I'm still playing with transparent borders and inheriting the correct border color to the `h1 a` plus I'm afraid I need another class `ui-collapsible-tabs-all-closed` to fix the bottom-left corner on the first tab. 

Still maybe some stuff you can use (UI tabs seems to be without CSS in latest JQM). Otherwise close as you see fit.