feat(game): put friends, group, inventory, skills in Game instead of Character

feat(packets): add many new packets

feat(game): handle null skill vnum in su packet responder

fix(packets): correctly use cast id instead of vnum in UseSkill packet

feat(game): respond to skill use packet sent from the client to set cooldown early

fix(game): set health to 0 on entity death

Merge pull request #8 from Rutherther/game-objects

Game objects

feat(game): add handling of packets for maps and entities

fix: use correct namespaces inside of game project

fix: use new packets in game responders

fix: use nos smooth packets in game

feat: add responders for character actions