Preparation for complete
monochrome support.
JIRA issue: CORE-15990
- Add IDM_COLORSGRAYSCALE
and IDM_COLORSMONOCHROME
menu items.
- Add PAL_GRAYSCALE and
PAL_MONOCHROME palette
modes.
- Add PaletteModel::CreateDitherBrush
helper function to create a
dithered brush.
- Use the dithered brush on
PAL_MONOCHROME in drawing
the palette window.