Remove jQuery UI handles from 'load-scripts.php' when on the CBOX Theme Options page.

As of WordPress 3.6, WP bundled newer versions of jQuery UI that interferes
with the functionality on the CBOX Theme Options page.  To workaround this,
we loaded older copies of jQuery and jQuery UI (see #169).

However, there were still edge-case instances where WP was loading newer
versions of jQuery UI with load-scripts.php.  load-scripts.php dynamically
generates a minified and concatenated version of several javascript assets,
including some jQuery UI scripts.

This, most notably, created an issue when attempting to use the image
uploader on the CBOX Theme Options page.

To address this, this commit aggressively removes all jQuery UI handles
from load-scripts.php.  This is a workaround until the CBOX Theme Options
page is rewritten to use the latest versions of jQuery / jQuery UI.

See #224.