CSS Fixes to Remove Dynamic Styling and <h2> tags

Please review this change for updating the styling of the jquery_pivot object. A summary of the reasons for the changes is below:

* I had issues specifically with the ```<h2>``` headers as my application does not support this type of styling. 
* The updates to the dynamic styling in the ```<div>``` tag was so I can create more flexible styling for this UI object.

I hope you find these useful. If you think any further changes should be made before submitting this, just let me know.

NOTE: This change should not affect the default appearance of the widget. If the stylesheet is included, the appearance will be identical to before the change. This allows any user to include their own style sheets for these elements in case they want a different look.