title: Mark mandatory fields on form, if not filled with valid value
body: <p>if you create a new dataset, mandatory fields which are not set yet are marked with a wiggly red line. </p>
  
  <p>it seems, that only string-values ( or several fields, but at least no integers ) are marked this way.</p>
  
  <p>if integer-references are used ( 1-based ), the regarding fields are filled with 0 per default which causes the red line to disappear.</p>
  
  <p>is there any way to leave those fields empty per default?</p>
  
  <p>thanks for hints!</p>