title: Drupal 7 - Add tab link to Node Edit Form
body: <p>Developing a module for Drupal 7 I can't seem to find how to add a link to neither the horizontal or the vertical tab when editing a node.
  I'm pretty sure I have to use hook_menu_alter but still... </p>
  
  <p><a href="http://i.stack.imgur.com/KYMYd.png" rel="nofollow">menu 1</a></p>
  
  <p><a href="http://i.imgur.com/kGwxB6e.png" rel="nofollow">menu 2</a></p>