bitmap corruption

[Mike Hearn]

if anybody wishes to tackle a fun bug, take a look at the imagelist
control in commctrl32 - it corrupts masks, giving some nasty visual
corruption esp on toolbar icons, but i've also seen it in winrar.

i suspect the _read_bitmap function doesn't do 1bit images correctly,
but didn't really manage to find out. i might have another crack
tomorrow, but in case somebody is looking for a job.... :)