[D&D] Inline image from inline editor

[Szymon Cofalik]

D&D image from inline editor into other editor have incorrect results.

Browser: Opera, maybe others.

Steps to reproduce:

1. Setup your editors like this:

   <div id="classic">
   	<img alt="CKEditor logo" src="/tests/_assets/logo.png" />
   </div>
   <div id="inline" contenteditable="true">
   	<img alt="CKEditor logo" src="/tests/_assets/logo.png" />
   </div>
   <script>
   	CKEDITOR.replace( 'classic' );
   	CKEDITOR.inline( 'inline' );
   </script>
   

2. Try to D&D the image from inline editor into classic editor.

Expected result: Image is correctly drag and dropped from one editor into another.

Result: Nothing happed.

Note: Everything works fine if you type some text, select the image with the text and D&D with the text.
Note: Same happens when the destination editor is also inline.
Note: During playing with this bug I managed to get string like data:image/png;base64,iVBORw0KGgoAAAA... as a result of D&D, but I can't reproduce it now :(

You can test it here: ​http://tests.ckeditor.dev:10450/tests/plugins/clipboard/manual/draganddrop

[Jakub Ś]

From what I have checked, D&D for inline images seems to work in CKEditor 4.5.7 just fine.

I have checked D&D between inline editors and classic/inline. All work as expected. Problem most likely has expired on master.