Changelog proof-read and corrected.
Fixed URL in Changelog.
Cleaned up outdated TODO comments.
Image button does not allow link - link has to be allowed by other feature to enable this dialog.
Merge branch 't/10195' into major
Set rule variable, because following conditions test it.
Standardize all ACF rules before pushing them to filter.allowedContent.

Also: function and regexp based validators have been dropped.
Merge branch 't/10191' into major
API docs fixes.
Use config.justifyClasses when setting justify feature's required content.
Merge branch 't/10213' into major
Use editable#attachListener to add listener to document element.
Merge branch 't/10219'
Link without href shouldn't be removed if isn't empty; ACF should clean up data-cke-saved- attrs.
Merge branch 't/10224' into major
Do not use outdated document instance.
Merge branch 't/10212'
Introduced align<->float transformation used in image plugin.
Merge branch 't/10166' into major
Fixed horrible code-style of autogrow resizeEditor().