Update, as requested.

After the recent configDialog.py changes, very little changes to it are
required.

I've included a much updated version of tabbedPages.py in this patch.
Since posting the original patch, I've discovered and fixed a few bugs,
implemented a 3d look for the tabs, and cleaned up the code. This
version has also been tested more thoroughly.

Also, this version very nicely supports tabbed panes with more than one
row of tabs. However you can't see this with configDialog.py, you'll
have to use the test code to check it out (just add several new pages
and then play around with them). I've used this feature in implementing
the extension config dialog, where every extension gets its own tab. I
hope I can finally get to posting a patch for it...

Enjoy!