Gtk3 for Xfce 4.12?

[Nick Schermer]

Devs,

Now 4.10 is out in the wild, it is time to look at the 4.12 roadmap and 
a part of that discussion is whether we want to port Xfce to gtk3.

The API (or lack of it) is not a problem I guess, since I think most of 
code compiles with deprecations disabled.

Theming? Not really my thing but I guess a couple of people can tell 
which version of 3.x we require for good theming (read: equal to gtk2). 
Is this even possible?

Plugins: porting will be a lot of work in the core modules, not too 
much for panel plugins, but this this needs to be done.

Anything else? Serve performance hits we know about?

The porting should happen in branches until at least all of core works 
with gtk3. But that is something we can decide once we made a decision.

Nick