Add world handling (and fall to ground)

- World is now properly parsed and stored from chunk data
- Block changes are also handled and world updated accordingly
- Added ground checking, the player will move down to reach the ground
- Performance tweaking in Protocol18, using lists instead of arrays
- Fix player look not properly skipped causing invalid location after
teleport

MinecraftClient/Protocol/IMinecraftComHandler.cs

@@ -24,6 +24,7 @@ namespace MinecraftClient.Protocol
         string GetSessionID();
         string[] GetOnlinePlayers();
         Location GetCurrentLocation();
+        World GetWorld();
 
         /// <summary>
         /// Called when a server was successfully joined