Updated beforeSave footprint for 2.4.

Signed-off-by: Jonathan Bruder <bruder@bcm.edu>
Merge pull request #4 from jonathanbruder/2.4

Updated beforeSave footprint for 2.4. Thanks for the contribution, @jonathanbruder.
Merge remote-tracking branch 'upstream/master'

Conflicts:
	Model/Behavior/NullableBehavior.php