title: add custom metadata namespace in CQ DAM
body: <p>I'm trying to add custom metadata namespace to CQ DAM.
  I. e. URI <code>http://example.com/</code> with prefix <code>ex</code></p>
  
  <ul>
  <li>added namespace in /crx/explorer/nodetypes/index.jsp in Namespaces tab</li>
  <li>added line <code>&lt;ex = 'http://example.com/'&gt;</code> in <code>/libs/dam/nodetypes/dam.cnd</code></li>
  <li>created <code>/libs/dam/options/metadata/ex</code> folder</li>
  </ul>
  
  <p>then I can't set <code>metadata</code> property to the <code>/libs/dam/options/metadata/ex</code> folder, nor add any subnode to it. ("No matching property definition found" error).</p>
  
  <p>What is the full procedure of adding custom metadata namespace in CQ DAM?</p>