A first part of the layers/masks patch

[Cyrille Berger]

On Saturday 26 September 2009, Dmitry Kazakov wrote:
> > for a,b,c) it doesn't work perfectly, but it's not that broken.
> 
> But still not usable =(
Well now, I have fix all the issue with the alpha colorspace (I have added 
alpha darken). All it remains to do is to make mask support the indirect 
painting interface.

It doesn't use the gray color, but this is by design, it means you have to use 
the opacity setting (this is something we have been debating in krita for 
years, wether opacity belongs in the tool or in the color selector).
Gradient work if you choose a gradient with transparency, in a future release, 
it could be worth investigating adding an option to the gradient tool for 
working on the transparent channel instead of colors (I think it might have a 
broader use).

-- 
Cyrille Berger