In preparation of pixel movement, I want to refactor our slowdown system to something more modular, and something that doesn't require /quite/ as many proccalls/calculations a tick. The way this works is intended to only have things recalculate when it's necessary, rather than calling it every move.
However, I've left movement_delay() in, as without completely redoing a lot of code it's not /quite/ ready at this point to tear it out completely, but I'm hoping everything can be transitioned over to this system later.
b5e2daa978