LPS-23733 - Update themes plugin compatibility with IE8, IE9, Chrome, and Firefox

Hey Nate,

Can you review these changes I've made to the themes?  This ticket can be found at http://issues.liferay.com/browse/LPS-23733.

Here are some notes for you to review:

- Check themes in Chrome, FF, Safari, IE 9, 8 , 7, 6

Some of these issues might occur only in IE6, but give a crack at seeing if they are simple fixes.

- Brochure theme search bar overlaps site title
- Emerald theme has issues with navigation
- Illuminate theme has issues with navigation
- Noir theme move background image in html to .popup
- Sample-HTML 4 theme has the popup window buttons cut off
- Sample-Unstyled theme has the popup window buttons cut off
- Section 508 theme portlet icons missing
- Seven Cogs theme has bullet image for list items
- SO theme has not been reviewed yet (Not sure if we are to review this theme)?
- Spurt theme "Powered by" footer is behind body content
- Tuxedo theme has issue with navigation
- Wordpress Kubrick theme has space below the header
- Zen theme does not render correctly

Please let me know if you have any questions.  Thanks!

- Jon Mak