Attack override

Implemented an attack override that goes before anything else.
If you return 1 in the weapon overridden function it adds a delay and exits so that it behaves like a normal attack.
if you return null or 0 it continues on.
Warning you have to handle everything yourself if you override it, like adding fingerprints and stuff.

Fixes https://github.com/tgstation/-tg-station/issues/761

See guys! this thing is useful!