title: Symfony 2 doctrine onUpdate cascade
body: <p>I am using Symfony2, Doctrine 1.2 and Doctrine/ORM 2.2 for one of my projects.
  I am trying to make one of my entities to cascade one of its foreign keys "onUpdate".
  This is pretty clearly not supported by doctrine ORM annotations. However, I really need to have the ability to auto-update this foreign key in both tables. </p>
  
  <p>Is there any way to do this?</p>
  
  <p>Thanks in advance for any help!!</p>
  
  <p>Cheers!</p>