Add Aftermath units; most without special logic. Seperate Cloaking from Submarine behavior. Fix crash when selecting unit with no speedmodifier traits. Add "Cannot deploy here" build notification.

OpenRa.Game/Traits/Submarine.cs

@@ -0,0 +1,50 @@
+using System.Collections.Generic;
+using System.Linq;
+using OpenRa.Game.Graphics;
+
+namespace OpenRa.Game.Traits
+{
+    class Submarine : IRenderModifier, INotifyAttack, ITick
+    {
+        int remainingSurfaceTime = 2;		/* setup for initial dive */
+
+        public Submarine(Actor self) { }
+
+        public void Attacking(Actor self)
+        {
+            if (remainingSurfaceTime <= 0)
+                OnSurface();
+
+            remainingSurfaceTime = (int)(Rules.General.SubmergeDelay * 60 * 25);
+        }
+
+        public IEnumerable<Tuple<Sprite, float2, int>>
+            ModifyRender(Actor self, IEnumerable<Tuple<Sprite, float2, int>> rs)
+        {
+            if (remainingSurfaceTime > 0)
+                return rs;
+
+            if (self.Owner == Game.LocalPlayer)
+                return rs.Select(a => Tuple.New(a.a, a.b, 8));
+            else
+                return new Tuple<Sprite, float2, int>[] { };
+        }
+
+        public void Tick(Actor self)
+        {
+            if (remainingSurfaceTime > 0)
+                if (--remainingSurfaceTime <= 0)
+                    OnDive();
+        }
+
+        void OnSurface()
+        {
+            Sound.Play("subshow1.aud");
+        }
+
+        void OnDive()
+        {
+            Sound.Play("subshow1.aud");		/* is this the right sound?? */
+        }
+    }
+}