graphical stuff.
lcd_bitmap() with the last argument set to 'false' now only OR the bitmap to
the background instead of using XOR as it did previously. I really can't see
the point in XORing...
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@1011 a1c6a512-1295-4272-9138-f99709370657