Kill Tracker - Add unit object to kill event params

[PabstMirror]

No description provided.

[Drofseh]

This gets the distance at time of death which may give a much shorter or longer distance for kills compared to the distance when the shot was fired.
For example, if the target is hit and goes uncon but takes a while to bleed out and the shooter moves up, or for shots from fast moving players such as pilots.
Do we care about these edge cases?

[PabstMirror]

I guess we would need to save the distance whenever we get an incoming wound
I don't really need this level
So I'll just send the unit object in the event