mouse interaction

after meddling with the animations for a bit the urge to... interact overcame me. Thankfully some people have already made mouse interaction PS forks, so implementing it was not too inconvenient. Required lots of copy-pasting though, glad multicursor is a thing otherwise I'd still be adding [ interact ] to rules...

Anyways now you can draw and stuff. Next up is smoothing out some animations, level select and bigger maps and then I suppose I'm done with this :)