Node State for "currently researching"

[mileswest07]

Request to add another node state for items that are currently undergoing research, to go along with "fogged", "researched", and "unlocked"

(Or is there a function that provides an animation for currently-researching items? For instance, a developer would like to add a progress wheel or progress bar overlaid onto the research node, to show that the item is currently being researched.)

[7yl4r]

I can create a new state easily, but I think I'll hold off on the animation for now. It's definitely on the wishlist, but I think I need to do some more code cleanup first.