Experimental (work-in-progress) Windows 8 look-alike theme.

At least I think it is Windows 8 (I don't own a copy) - I am working of
screenshots I found on the internet. I liked the look, so thought I
would start on a fpGUI theme for it.
Adds the new win8 theme unit to the fpgui_toolkit package
Richview resize/render speed

while testing richview I noticed it's fairly slow, though only if there
are font changes in the content. So I added a font cache to the richview
fontmanager and now there is almost no delay to render content in the
richview. Big, big speed improvement.