title: has_many :autosave => true skips validation when saving children
body: <p>In both Rails 2 and Rails 3, if :autosave => true a has_many association, the collection is looped through and save(:validate => false) is called on each child association.  Why is that?  We need a before_validation callback to run for that child object, but it won't since it's a save that skips validation.</p>
  
  <p>What's a good way around this?  And what is the purpose of skipping validations?</p>
  
  <p>Any help would be much appreciated! Thanks!</p>