title: Need tutorial for custom DialogPropertyValueEditor workflow foundation 4.0
body: <p>I have a custom activity which has inargument&lt;MyClass&gt;.
  MyClass has several properties.</p>
  
  <p>I want to provide a popup dialog editor for this inargument which will present a form, to input the values of all properties. </p>
  
  <p>Is there any good example, tutorial showing all the steps to implement this?</p>