title: Alter messages in Drupal 7
body: <p>There is a couple of messages in drupal. When there is a php warning, an error message is raised, but a module can also raise messages with drupal_set_message(). The question is: Is there a way to alter these messages? For example to replace every 'a' with 'b' in every message.</p>
  
  <p>Thanks!</p>