Flattentool

Fixed

- Use backports-datetime-fromisoformat only if needed, to fix PyPy 3.7 support https://github.com/OpenDataServices/flatten-tool/pull/386

Removed

- We no longer support Python 3.5

Fixed

- Don't fail when an .ods column header is empty https://github.com/OpenDataServices/flatten-tool/issues/378

Fixed

- Fix another number formatting .ods bug https://github.com/OpenDataServices/flatten-tool/pull/383

Changed

- Reduce memory footprint of flattening https://github.com/OpenDataServices/flatten-tool/pull/376

Fixed

- Fix parsing date and number formatting from .ods files https://github.com/OpenDataServices/flatten-tool/pull/373

Fixed

- flattening: Uses much less memory by storing data in a embedded ZODB database, using ijson and using write only mode in pyopenxl.
- use-titles: Use $ref'erring title if available https://github.com/OpenDataServices/flatten-tool/pull/368
- create-template --no-deprecated-fields: Did not work if deprecated element at same level as a $ref https://github.com/OpenDataServices/flatten-tool/issues/185#issuecomment-719587348

Fixed

- Don't fail if compiled translation files (.mo) don't exist, and Django isn't installed
- Fix some incorrect assumptions about types
- Allow XML IDs to be attributes