[OpenRaster] proposal: new layer modes, ref updates, extra properties for layer groups, impact on apps

[Andrew Chadwick]

Any more feedback on this? Boud mentioned on IRC that he thinks it
looks OK, and we had a bit of a to-and-fro on #gimp about it. People
are beginning to nag me on Twitter about getting it integrated with
MyPaint master now.

Since the changes in the latest proposal are pretty minimal, I'd like
to move ahead with it in the next week. Would that meet with
everyone's approval?

Quick Q: do we need to any more more than svg:dst-in and svg:dst-out?
We could add all the Porter-Duff modes, but they're not all equally
useful! Destination In/Out seem to be the most useful for masking an
isolated stack. Off the top of my head, svg:src-atop might be of some
limited use to artists too - the rest, not so much. I'm tempted to add
them all for completeness however. Any objections?

-- 
Andrew Chadwick