Fixed problems (basically rewrite)

I might have overdone this, but this works (at least when I test it)!
I removed the per-world sleep list and made a list for all worlds for the player is (no longer) sleeping messages.
The checking of the amount of sleeping players now just goes through all players in the world and checks them.

Don't feel forced to pull this, you probably doing this for fun, I don't want to ruin that :P It was fun to work on something else, so I don't mind if it isn't used :)