Loading and CMAP8

Hello again,

I'm still working on the yY requests.  My handling of depths <8 is
starting to come together, but I still have work to do to get
multibyte pixels working.

This week, I plan to implement the CMAP8 format and start work on the
font requests as a major application of the image-loading support.  As
a bonus, I'm pretty sure that the font code will serve as a pretty
good exercise of the image-drawing facilities, and I suspect it will
uncover lots of bugs!

I haven't been able to connect my laptop to the Internet this week
(I'm sending this from a borrowed machine), so I haven't uploaded the
code yet.  It'll be back to normal by Wednesday though!

-- David