title: Stick with generic ErrorHandler.js while allowing custom errormessage handling per request and not have double message boxes
body: <p>The generic ErrorHandler which is an extension and hooked onto every component's main model request is useful for unexpected errors.
  However, when I'm creating new entities I want to report with user friendly messages. These messages are composed in the gateway and passed in the RAISE clause. Currently this causes to seperate message boxes to popup, one from the ErrorHandler, one from my onErrorHanlder that I pass to oModel.create().</p>
  
  <p>How can I keep the generic one, but not use it in this case?</p>