New features
[3351cc0][473e843] Add flash support on login page (@bastien70)
[49dd946] Add support for label_html FormType option (@vic-blt)
[f1e3619] Update TomSelect.js library dependency to fix bugs with required autocomplete fields (@javiereguiluz)
[fd76fb0] Allow dbal ^3.0 to be installed (@vasilvestre)
[c7557a6] Add a new "table footer" block in Twig templates (@parijke)
[5af50ac] Translate the autocomplete widget messages (@javiereguiluz)
Bug fixes
[f444a3b] Fix user drop-down menu (@gbere)
[5b288b5] Remove unneeded admin URL generator dependency on form factory (@Ang3)
[680c41a] Fix bug in default value (@loevgaard)
[6e6b127] Don't show the clear button in required autocomplete fields (@javiereguiluz)
[da15a04][599c2b6] Fix bug in Image field related to texts & buttons updating (Mickael Bidinger)
[8af0cc0] Fix bug in Image field related to check delete-checkbox when file should be deleted (@andreasschacht)
[6211fe4] Fix the name of a custom HTML attribute (@javiereguiluz)
[e6462bb] Display a better error message when using date/time fields without the Intl extension (@javiereguiluz)
[4ccbcbb] Update Vich delete label to match current translation keys (Jon Green)
[798cc9a] Fix collection_row data-num-items to make ID unique (Mickael Bidinger)
[430ab16] Fix deprecation relaed to HttpFoundation InputBag (@xaviermarchegay)
[4024fae] Fix 404 link to Unicode docs (@xaviermarchegay)
[738bb8a] Update French translation (@Ang3)
[71568a4] Misc. doc fixes (@jmsche)