Grenade modding on beta branch

Grenades are now moddable !

Changelog :
- Added Grenade modding
- Updated modding template
- Fixed a bug where most modded equipment were spawning at the same place on the player
- Fixed a bug where bots wouldn't spawn on classic maps
- Fixed a rare bug where grenades would despawn before exploding
- Fixed a bug where some sounds weren't played with modded weapons