Improve frag messages

[is-this-c]

You were killed by Default (Rail Driver)!
is changed to
You were killed by Default's rail driver!.

[GooberRF]

While I think this formatting change is a fundamentally good one... I'm not sure it's a good idea to make the formatting more descriptive and explicit as you've done, without also improving the logic used to determine the weapon.

Currently, if you fire a rocket, then swap to pistol, and your rocket kills a player, they will get a message stating You were killed by Default (12mm Pistol)... not ideal, but somehow I think it's even less ideal if it specifically says You were killed by Default's 12mm pistol despite that being just flat wrong.

I know what I'm saying isn't an issue with your PR, but to some degree I think the change in this PR exacerbates the existing issue. I'm not saying this PR should be held back, but it would certainly be ideal to improve the logic at the same time.

[is-this-c]

It would be nice but it is not so simple to fix what you are talking about. I do not feel motivated to fix it at present so I think it best to merge.