* Add creation_date to the serializers of the Orders (to make it changeable by API)
Fixes#6159
* Add API tests for the creation_date field
* Fix missing , in test_api.py
* Allow null to be passed (transleted to current date later) for creation_date of the Orders in the serializers too
* Add user settings to remember the last/favourite label template
Fixes#4932
* Remove settings_value from translated templates
Thanks Oliver for the hint!
* Support structural part categories
Structural categories cannot have parts assigned (only sub-categories)
Fixed#3897
* Fixed unit test
* Fix Oliver's review comments
* Add option to recursively delete part categories
Fixes#3384
* - Added test (broken ATM)
- Refactored parameters to booleanish
* Fix styling issues reported by flake8
* Working on unit testing
* Added on_commit debugging callback
* Separate the recursive part of the deletion into another method
to make sure that the delete operation is performed in a single transaction
* Trying transactions with @transactions.atomic
* Fix flake8 reported issues
* Removed unused debug callback
* Fixed tests for category recursive deletion
* Fix flake reported issues
* Fix flake reported issues
Again
* Remove unrelated formatting changes
* Fixed a part of review comments
