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- Implemented ability to include config files for file-based stores.
+ Syntax: include path/to/included.ini
+ A new `IncludeObserver` component listens to the changes of the included
files and will update the config of the including file on
modification. Added and removing new included files is also supported.
- Dropped support for Python 3.6
- Added support for Python 3.9
- Removed last compatibility code with Python 2.
- Applied zopefoundation.meta config