Release 2.2.0 - https://github.com/Ecodev/formule/compare/2.1.2...2.2.0

[TASK] Remove leftover of TYPO3_DB
[TASK] Remove field is_sent
[TASK] Complete Doctrine migration
[BUGFIX] Correct SQL list of fields
[BUGFIX] Completly remove deprecated DatabaseConnection
[BUGFIX] Replace deprecated DatabaseConnection by Doctrine