This updates the base models, destination models, and the SQLite SQL

datasets to include two DateTimeField and two DateField instances,

which will be useful for testing some operations.
Only the SQLite datasets are updated, as it's the only type of database

that has to create tables and move data as part of a field change

operation. MySQL/MariaDB and Postgres don't require any updates.

All unit tests pass for all versions of Django and all databases.