Input - Added basic input stuff

src/Artemis.Storage/Entities/Surface/DeviceEntity.cs

@@ -1,12 +1,27 @@
-namespace Artemis.Storage.Entities.Surface
+using System.Collections.Generic;
+
+namespace Artemis.Storage.Entities.Surface
 {
     public class DeviceEntity
     {
+        public DeviceEntity()
+        {
+            InputIdentifier = new List<DeviceInputIdentifierEntity>();
+        }
+
         public string DeviceIdentifier { get; set; }
         public double X { get; set; }
         public double Y { get; set; }
         public double Rotation { get; set; }
         public double Scale { get; set; }
         public int ZIndex { get; set; }
+
+        public List<DeviceInputIdentifierEntity> InputIdentifier { get; set; }
+    }
+
+    public class DeviceInputIdentifierEntity
+    {
+        public string InputProvider { get; set; }
+        public object Identifier { get; set; }
     }
 }