Make `Model::markModified()` public
Update mediaelement.js to version 2.13.1 (see #6318)
Add support for "countBy" to `Model::__callStatic()` (see #5984)
Add some validation logic to the `Result::data_seek()` methods (see #6319)
Correctly reference `$GLOBALS['BE_MOD']` in `Backend::getBackendModule()` (see #5915)
Support the "autocomplete", "autocorrect", "autocapitalize" and "spellcheck" attributes (see #6316)
Load the code editor when editing the HTML form field
Show the teaser text of redirect events in the event list (see #6315)