Airlocks rewritten to use appearances, use less ugly sprite from Eris.

Content.Shared/GameObjects/Components/Doors/SharedDoorComponent.cs

@@ -0,0 +1,22 @@
+using System;
+using SS14.Shared.Serialization;
+
+namespace Content.Shared.GameObjects.Components.Doors
+{
+    [NetSerializable]
+    [Serializable]
+    public enum DoorVisuals
+    {
+        VisualState,
+    }
+
+    [NetSerializable]
+    [Serializable]
+    public enum DoorVisualState
+    {
+        Closed,
+        Opening,
+        Open,
+        Closing,
+    }
+}