[gnomemm] The Canvas still uses Pixmaps for stipples!

[ERDI Gergo <cactus cactus rulez org>]

I've reported this a long time ago for the 1.2 branch, but it looks like
1.3 also has this problem: stipple properties use Pixmaps as the property
type when in fact they should be Bitmaps.

Unless someone objects, I'll check in a patch tonight to fix this.
Otherwise the current stipple properties are not usable, regardless of how
deep we are in an API freeze.

-- 
   .--= ULLA! =---------------------.   `We are not here to give users what
   \     http://cactus.rulez.org     \   they want'  -- RMS, at GUADEC 2001
    `---= cactus cactus rulez org =---'
Eddig nem is tudtam, hogy a lézert is ki lehet nyomtatni.