More cleanups of custom classes in favor of .NET runtime types.

Source/Game/Entities/Object/Position.cs

@@ -15,9 +15,9 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-using Framework.GameMath;
 using Game.Maps;
 using System;
+using System.Numerics;
 
 namespace Game.Entities
 {

Source/Game/Entities/Object/Update/UpdateFields.cs

@@ -17,13 +17,13 @@
 
 using Framework.Constants;
 using Framework.Dynamic;
-using Framework.GameMath;
 using Game.DataStorage;
 using Game.Networking;
 using Game.Networking.Packets;
 using Game.Spells;
 using System;
 using System.Collections.Generic;
+using System.Numerics;
 
 namespace Game.Entities
 {

Source/Game/Entities/Object/WorldObject.cs

@@ -17,7 +17,6 @@
 
 using Framework.Constants;
 using Framework.Dynamic;
-using Framework.GameMath;
 using Game.AI;
 using Game.BattleFields;
 using Game.DataStorage;
@@ -28,6 +27,7 @@ using Game.Scenarios;
 using Game.Spells;
 using System;
 using System.Collections.Generic;
+using System.Numerics;
 
 namespace Game.Entities
 {