- Data is now stored in three separate files for items, assignments and rules. File format is simpler.
- Removed `authFile`. Added `itemFile`, `assignmentFile` and `ruleFile`.
-`createdAt` and `updatedAt` are now properly filled with corresponding file modification time.
-`save()` and `load()` are now protected instead of public.
- Added unit test for saving and loading data.
- Enh #4080: Added proper handling and support of the symlinked directories in `FileHelper`, added $options parameter in `FileHelper::removeDirectory()` (resurtm)
- Enh #4086: changedAttributes of afterSave Event now contain old values (dizews)
- Enh: Added support for using sub-queries when building a DB query with `IN` condition (qiangxue)