Created a set of extendable widget features to control look and feel of Image2 dialog.
Don't set alt attribute if disallowed.
Don't caption the image when figcaption is disallowed.
Don't align the image when alignments are disallowed.
Don't display the resizer when width/height are disallowed.
Don't set width and height if attributes are disallowed.
Disable justify commands when image alignment is disable by ACF.
Removed obsolete allowedContent reference in dialog definition.
Enforced requiredContent rule for the widget.
Since alt is mandatory for the widget, removed requiredContent rule in the dialog.
Cached filter check in alignCommandIntegrator to speed it up a little bit.
Used editor.filter#checkFeature instead of editor.filter#check.