Fix tabs and jQuery 1.9 compatibility

* Replace .toggle( max, min ) (deprecated); minor tweaks to showHideButton element
* Use jQuery UI collapsible support, rather than manual show/hide, which was
  causing bugs; rename tabs element.
* Use beforeActivate instead of show so there's no flash
* Replace events for clicks on tab links with handling in beforeActivate.
  Also move logic to update up/down show/hide button here, required for
  consistent state.
* Change terminology to match jQuery UI Tabs.
* Refactor template/dummy element creation to keep tabs element clean.

Fixes issue #187 and issue #189.
Merge pull request #193 from mattflaschen/fixjQuery1.9AndTabs

Fix tabs and jQuery 1.9 compatibility