title: Proper use of Column.ForeignKeyAction.CASCADE
body: <p>If I have a relation like this, and what I want is that whenever I call <code>delete()</code> on an <code>User</code>, the <code>vehicle</code> field is also deleted.</p>
  
  <pre><code>@Table (name = "Users")
  public class User extends Model {
      @Column(name = "Name", unique = true, onUniqueConflict = Column.ConflictAction.REPLACE) name;
      @Column(name = "Vehicle") Vehicle vehicle;
  }
  
  @Table (name = "Vehicles")
  public class Vehicle extends Model {
      @Column(name = "Name", unique = true, onUniqueConflict = Column.ConflictAction.REPLACE) name;
  }
  </code></pre>
  
  <p>I think this can be accomplished by using <code>onDelete = Column.ForeignKeyAction.CASCADE</code> on <code>Vehicle.name</code> but I'm not so sure so I'll just go ahead and ask.</p>