Edit atom legend in wysiwyg mode

Atom's legend can be edited, but only via the modal “Edit atom properties”, which is not very friendly, to say the least...

This can be done by theming legend as

function theme_sdl_editor_legend($variables) {
...
  return "
  <div class='meta' contentEditable='true'>
    <!--copyright={$atom->sid}-->{$atom->rendered->title}, {$by}<!--END copyright={$atom->sid}-->
  </div>
  ";
// instead of
  return "
  <div class='meta'>
    <!--copyright={$atom->sid}-->{$atom->rendered->title}, {$by}<!--END copyright={$atom->sid}-->
  </div>
  ";
}

I also suggest to move the copyright comment out of the div, to make it stay protected;
Also added a link...

  return "
  <!--copyright={$atom->sid}--><div class='meta' contentEditable='true'>
    <a target='_blank' href='atom/{$atom->sid}'>{$atom->rendered->title}</a>, {$by}
  </div><!--END copyright={$atom->sid}-->
  ";

To make it retroactive, just insert in plugin :

    // Prevents atom from being edited inside the editor.
    $(editor.document.$).find('div.dnd-atom-wrapper').attr('contentEditable', false);
+   // Allows atom legend to be edited inside the editor.
+   $(editor.document.$).find('div.dnd-atom-wrapper div.dnd-legend-wrapper div.meta').attr('contentEditable', true);

did not notice any damageable side effects...