[KOS] Two patches today

[Dan P. <ba...@al...>]

FYI: I checked in two interesting patches today. One from Andrew enables
polygon culling control in KGL, which is helpful for two-sided polygons
and translucent polygon usage. The other is a port of the MMU code from
KOS-MMU. I haven't tested it but it does compile and it worked in
KOS-MMU. I'll probably cook up a simple example a bit later.