title: Restrict which nodes can be referenced
body: <p>Is it possible to restrict the nodes in a node reference field to nodes, which were created by the current user?</p>
  
  <p>Imagine one node of the type x &amp; several nodes of the type y. Node x has an unlimited number of node reference field to nodes of the type y.</p>
  
  <p><strong>UPDATE:</strong></p>
  
  <p>An user has to reference several experiences to show his qualification for a certain project. All of his experiences are nodes of the type "project_experience" which has to fields:<br>
  1. one project (node reference to content type "project")<br>
  2. one description of the function and experience in this project.</p>
  
  <p>When creating a node "project_application" the user should decide which of his experiences/projects are specific to the project he is applying to.</p>