Added DamageEntity.Vehicle messages

Added the missing vehicle messages, also changed serverside since it was
unnecessarily rounding results from math.random ( math.random always
returns ints )
Killer/victim comparison is now more reliable, removed kill reward ( to be moved to freeroam )

Changed the victim/killer comparison to SteamId instead of Name, kill
reward will be moved to freeroam.
Merge pull request #1 from FabioGNR/master

killfeed new messages + minor improvements