Adjust project structure

src/Shared/HandyControl_Shared/Interactivity/IAttachedObject.cs

@@ -0,0 +1,12 @@
+using System.Windows;
+
+namespace HandyControl.Interactivity
+{
+    public interface IAttachedObject
+    {
+        void Attach(DependencyObject dependencyObject);
+        void Detach();
+
+        DependencyObject AssociatedObject { get; }
+    }
+}