Sorry I don't have much time tonight to get a closer look at the code, but a quick test showed me a regression (yay me for not writing any tests).

You can't directly click on an upgrade anymore to activate the skill+the upgrade at the same time. Seems to be because of this code removal where we linked upgrades and skill for the view. I remember now you asked me about that and I actually don't remember if I answered :D

Cheers,
Leimi