Added the initial functionality for pickup bonuses and simple VFX. I had the idea that when the bonuses appear they will sketch themselves in. That's why there's all the sketch stars in the screenshot. It's a hand drawn animation which is a style I might adopt for other things. When they finish appearing they will take on a more solid form, but I haven't got round to that yet.

I've been having some issues with the garbage collector triggering more often than I'd like. I tracked one problem down to me creating a new matrix array everytime I drew a sprite - which was alot of matrices. I fixed that one, but there seem to be some less frequent ones still cropping up now. I'll track it down.