Exiled the game engine specific broadcast functions like `abs` to a separate `vectors/game.nim` for now. Also refactored those on to the broadcast template, and enforced the naming scheme. It should have been `absed`, `maxed`, etc, since the lib generally uses past tense to denote copying functions and present tense for mutating ones.
i'm not sure much else needs to be moved to `/game.nim` type files. _most_ of the interface is mathematically correct. i don't see a problem putting the very common things that are not correct yet are very common in practical use in a side file like this because it makes the symbols optional without too much overhead.
