Theme Installer fixes:
 * Better more filters section. props sonjanyc for some mockups.
 * Better handling of no results.
 * Use # for hrefs.

props matveb.
see #27055.


git-svn-id: https://develop.svn.wordpress.org/trunk@27896 602fd350-edb4-49c9-b593-d223f7449a82