More than 2000 lines of code less in app/, instead of
if (instance->member)
{
g_object_unref/g_free/g_whatever (instance->member);
instance->member = NULL;
}
we now simply use
g_clear_object/pointer (&instance->member);
Add a "mask-only" property to GimpBrushClipboard. When TRUE, only
create a brush mask (not a pixmap brush with mask and image).
Keep two clipboard brushes around: one classic "Clipboard Image" one
to be used as "stamp", and one new "Clipboard Mask" one that turns the
clipboard into a brush mask.
