API docs and changelog corrected.
Merge branch 'master' into major
Made filter understand wildcards.
Removed a trick which was obfuscating code.
Fixed a bug - nothingRequired was always false, because empty array is a truly value.
Handle required properties with wildcards.
Changelog entry.
Merge branch 't/10202b' into major
config.captionedClass config option to control CSS class of captioned image.

Conflicts:
	plugins/image2/plugin.js
config.captionedClass considered in widget's template.
config.captionedClass considered while upcasting and checking for centering wrappers.
config.captionedClass considered in ACF rules of widget definition.
config.captionedClass updated default classes of captioned images in samples.
Updated doc strings.
Fixed: Misplaced resizer because of line-height in non-captioned widget.
i18n of figcaption placeholder made possible.
Extended dev sample to check whether custom attributes survive state shifting.
Moved Image2 style definition to contents.css.
config.image2_alignClasses defined in the plugin
config.image2_alignClasses considered in ACF rules.