Record KBs for units controlled by the player

- Record KBs on _DAMAGE events with an overkill argument >= 0 in
addition to PARTY_KILL
-- Suggested by Caellian because PARTY_KILL apparently doesn't fire
correctly sometimes
- Add globals list and tools-used entry for mikk's FindGlobals script
- Re-encode core.lua as UTF-8 without BOM so luac will work
Fix tools-used entry