[graph-tool] Edge weights in assortativity

Hi, I'm using graph-tool to analyze a network with edge weights that represent "multiplicity" or "frequency" of the relationship. Most of the algorithms in graph-tool accept a weight in this sense (where appliable), but the assortativity (or scalar assortativity) does not. I think it's possible to use edge weights in the assortativity coefficient (correct me if I'm wrong), is there any plan to introduce this feature? I think For what I've seen, I don't think it would be hard to implement, so I can put a pull request if you find it interesting, although someone would have to review it as I don't have enough RAM in my machine to compile graph-tool. -- Javier Dehesa