Multiple small changes

* Removed npc_bullseye from kill feed ( Dummy NPC )
* Changed default killer for npc to worldspawn
* Floor turret isn't killed by world when knocked down
* Disallow giving weapons from spawnmenu when not alive
* Added Gravity Gun and Zombine Grenade to spawnmenu
* Cleaned up game_ep2.lua
* Updated language files
* Removed unused settings files