- automatic upgrade of encryption key.
- automatic decryption of CI3 data, then re-encryption in CI4 and update of table.
- Fixing save function in app_config model
- Removed the CI3 Encryption library as it's no longer needed.
- Added a field to \App\Config\Encryption.php to allow cipher.
- Removed test code for CI3 encryption and added test code for CI4 decryption of CI3 data.