Modified behavior to fix strict warnings

When loading the plugin on PHP: PHP 5.4.4-14+deb7u4 (cli) (built: Aug 23 2013 14:37:41) following errors show up:

Strict (2048): Declaration of AuditableBehavior::beforeSave() should be compatible with ModelBehavior::beforeSave(Model $model, $options = Array) [ROOT/**/AuditLog/Model/Behavior/AuditableBehavior.php, line 312]
Strict (2048): Declaration of AuditableBehavior::afterSave() should be compatible with ModelBehavior::afterSave(Model $model, $created, $options = Array) [ROOT/**/AuditLog/Model/Behavior/AuditableBehavior.php, line 312]

Fixed by adding the 2 parameters which are un-used off-course.