Completed a working prototype in supporting themeroller themes in tabSet.

It was straight-forward to make the component use the Themeroller theme that
was loaded on the page. However, there were a few issues:

• CSS class names to represent the current state (e.g. active, highlighted, etc.)
  are hard-coded in the jQuery-ui Javascript code. So, it was necessary to override
  the CSS class names used by YUI. Fortunately, YUI uses fields like ACTIVE_CLASSNAME
  to hold the string value of the class name used for the active class (in YUI it's 'selected'
  by default, while in jQuery-ui it's ui-state-active).

• While the colors, fonts, and background images of the theme can be applied
  successfully to the component, the component doesn't look good right away. At the
  end, the theme CSS is only concerned with colors, fonts and background images and
  not so much with positions, spacing, margins, etc. So, it was necessary to add some
  structural CSS styles for the component to look good. These structural CSS styles were
  taken from jQuery-ui CSS.

• While the YUI Tabview and the jQuery Tabview widgets use a similar HTML structure
  to initialize the widget, we add and modify some of the markup in the component, which
  results in some styles not being applied correctly. So, it was necessary to make
  adjustments to the structural CSS styles to work with our markup. Further, it might be
  necessary to make some slight changes to the markup we render in order for the
  component to look completely right. For example, we are rendering a <div> element
  inside <li> elements to display the tab header; it was necessary to make some adjustments
  to the structual CSS to apply the theme to this <div> element, but the code only
  makes changes to the <li> element, so these changes are hidden by the styling of the <div> element.

added tabset themeroller compatibility fixes at revision 25231

Added some necessary styling for the case when the tab has cacheOnClient="true", at revision 25288.

There is an issue remaining in that there seems to be an extra vertical bar rendered at the right side of the tab labels, one for each tab label that exists. See attached snap (Screen shot 2011-08-24 at 5.33.40 PM.png).