title: TinyMce create toolbar dropdown containing more toolbar items
body: <p>This seems like it ought to be simple to do, but I'm having a hard time figuring it out.  I have a tinymce instance, and for various reasons I want to have all the toolbar items on one long line.  The problem is that there are slightly too many items for it all to fit so I'd like to create a custom button and put the toolbar items in there.  Something like:</p>
  
  <p></p>
  
  <pre><code>tinyMCE.init({
         ...
          setup: function(editor) {
            editor.addButton('insertMenu', {
                type: 'listbox',
                text: 'Insert',
                icon: false,
                items: 'code link'
            });
          },
          toolbar1: 'insertMenu undo redo | bold italic |alignjustify | ...
  </code></pre>
  
  <p>Obviously that doesn't work because the items: 'code link' isn't correct for a listbox.. but it I'd hope it's possible to do this sort of thing in tinyMCE.  Yes I have looked at examples like <a href="http://www.tinymce.com/tryit/3_x/menu_button.php" rel="nofollow">http://www.tinymce.com/tryit/3_x/menu_button.php</a> but they always contain text links etc. whereas I just want to reuse the existing toolbar icons and functionality.</p>