Debug touch support on tablets/phones

[maximecb]

NoiseCraft seems to work well on laptops and desktops, but on my android phone, I can't manage to move a node or select nodes. I don't really get why it doesn't work. The JavaScript pointer API is pretty unintuitive.

I think a fair bit of work would be needed to properly support tablets, for instance, keyboard shortcuts aren't going to be usable on tablets, but it might still be nice to get touch screens and touch devices working better than they are now. For example, if people could at least change the values of knobs on tablets and move nodes, that would be a nice improvement. There are also laptops with touch screens nowadays.