title: Using this.Context inside BeforeSaveEntity
body: <p>I was looking for a good way to organize validation rules within BeforeSaveEntity method and I have found this comment in the file: TodoContextProvider.cs within the project: BreezeMvcSPATemplate:</p>
  
  <pre><code>// A second DbContext for db access during custom save validation. 
  // "this.Context" is reserved for Breeze save only!
  </code></pre>
  
  <p>Why this.Context can not be used?</p>