Admin settings interface tweaks

Hi Baris,

I like your Google Fonts module very much, but I kinda got lost in the huge list of available fonts and couldn't easily see which fonts I had already enabled without a lot of scrolling. That gave me the idea to split up the available fonts and the enabled fonts into two collapsible fieldsets. I've attached a PATCH file and screenshot with my changes. Please consider applying the patch to your module. The base for the PATCH is the 7.x-1.x-dev state of Feb 4, 2011.

What the PATCH does:
- Split up the font listing into two collapsible fieldsets "enabled fonts" and "available fonts".
- Off course, the fonts that are in the enabled fonts fieldset do not appear in the available fonts fieldset anymore...
- If there are no fonts enabled, a message is displayed, the enabled fonts fieldset is not rendered and the available fonts fieldset is uncollapsed.
- If there are fonts enabled, the enabled fonts fieldset is rendered and the available fonts fieldset is collapsed
- If all available fonts are enabled (highly theoretical and not desired in any case, I know), the enabled fonts fieldset is rendered and the available fonts fieldset is not rendered. A message is displayed.

I have some other suggestions, that I will put in a seperate issue for consideration...

Kind regards,
Martijn