Removed unused using directives.

OpenRA.Game/Traits/Interactable.cs

@@ -12,7 +12,6 @@
 using System.Drawing;
 using System.Linq;
 using OpenRA.Graphics;
-using OpenRA.Traits;
 
 namespace OpenRA.Traits
 {

OpenRA.Game/Traits/Selectable.cs

@@ -9,10 +9,6 @@
  */
 #endregion
 
-using System.Collections.Generic;
-using System.Drawing;
-using OpenRA.Graphics;
-
 namespace OpenRA.Traits
 {
 	[Desc("This actor is selectable. Defines bounds of selectable area, selection class and selection priority.")]

OpenRA.Game/Traits/TraitsInterfaces.cs

@@ -13,7 +13,6 @@ using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using System.Drawing;
-using OpenRA.Activities;
 using OpenRA.FileSystem;
 using OpenRA.Graphics;
 using OpenRA.Network;