Initial test of multistep dialog workflow.
Fixed error messages not shown if nothing selected on the 'select' embed step.
Merge branch 'entity-manager-helper' into dialog-multistep-form

Conflicts:
	src/Form/EntityEmbedCKEditorSelectForm.php
Merge branch 'entity-manager-helper' into dialog-multistep-form
Added docs for accessEntity().
Merge branch '8.x-1.x' into dialog-multistep-form
Rename CKEditor form to EntityEmbedDialog
Modify Ajax, JS to work with new attributes
Change hyphen separated attribute names to be underscore separated
Fix syntax errors
Prefix attributes with data_ as returned by form in the response
Remove obsolete files
Remove debug log statement
Add all attributes using a for loop instead of hard-coding those
Revert to use underscore separated attribute names
Add placeholder text to ensure that the div is not discarded
Revert to use underscore separated attribute names
Set entity ID along with UUID.
Tweak dialog title.
Merge pull request #39 from drupal-media/dialog-multistep-form

Convert embedding dialog to use a multistep form instead of two separate forms. Cleaned up data attribute handling.