- Add untested support for ARC9 Weapon Base

- Disable killing live NPCs from disconnected players by default
- Add Melee Arts 2 support
- Added support for removing launched objects (only Melee Arts 2 used this, but the option is available in the code for anyone who wants to apply it in other cases. Many addons can be and need to be put into this filter)

- Fix some script errors caused by nil entities

Changes by Shark-vil:

- Added a NPC removal override hook;
- Optimized removal of disconnected players NPCs.

- Remove corpses by default when "Keep Corses" is on

- Fix crash caused by a game update
[EDIT] This update was useless, I was having one of those bugs we solve by restarting the computer.

- Fix trying to access GAMEMODE too early
- Clear "Creator" field form dead NPCs
- Attempt to remove contents created very late (Better VJ Base support)

- Hide "Abandoned NPCs" option in singleplayer

- Fix addon sometimes incorrectly removing sweps, sents and ragdolls created by players
- Add option to control GMod "Keep Corpses" support
- Rename the option "Kill Abandoned NPCs" to "Abandoned NPCs"
- Add option to control "weapons dropped by live players" removal

- Don't remove corpses if Keep Corpses is on (ai_serverragdolls 1)