Idea: drop the condition KillSelf for superweapon

[dnqbob]

Although KillSelf is a good idea on instant kill but it has a bug:

When I use superweapon, the actors is killed by KillSelf count as victim player score, which present a weird/funny thing that when AI will always get a high score when I use superweapon kill a bunch of its units.

So could we just use a very high damage warhead instead of Killself for this effect? we can also save a trait on that.

[ABrandau]

That might be the easiest solution on the short term so yeah.