Merge branch 'dev' into f-filesystem

CHANGELOG.md

README.md

RELEASE_GUIDELINES.md

release.sh

setup.py

src/caosdb/apiutils.py

src/caosdb/common/datatype.py

src/caosdb/common/models.py

src/caosdb/connection/connection.py

unittests/record.py

unittests/test_add_property.py

unittests/test_apiutils.py

unittests/test_datatype.py

unittests/test_entity.py

unittests/test_property.py

unittests/test_record.py

unittests/test_record.xml