Resolve warnings and change init order

Initialize dConfig first, before logger so we know whether or not to log to console
Initialize namespace Game variables to nullptr so they are a known value if accessed before initialization.
Removed unused Game variables
Replaced config with a pointer instead of referencing something on the stack.
Assign return values to system calls to silence warnings.

Tested that the server still compiles, runs and allows me to load into the game.

dCommon/Game.h

@@ -5,7 +5,6 @@
 class dServer;
 class dLogger;
 class InstanceManager;
-class dpWorld;
 class dChatFilter;
 class dConfig;
 class RakPeerInterface;
@@ -16,7 +15,6 @@ namespace Game {
 	extern dLogger* logger;
 	extern dServer* server;
 	extern InstanceManager* im;
-	extern dpWorld* physicsWorld;
 	extern dChatFilter* chatFilter;
 	extern dConfig* config;
 	extern std::mt19937 randomEngine;