Many problems with Document Properties Plugin and setting doctype

[Jakub Ś]

To reproduce:

1. Go to Document Properties sample and open docprops dialog
2. Set document type to XHTML1.1 and click Ok.

Results:

1. If you looked on HTML with firebug or other webtool before changing the doctype in dialog and afterwards. You will notice that doctype is HTML5 declarations for both cases. You have to switch to source and back so that browser could see the difference. Reproducible in all borwsers.
2. If you click preview button and look at HTML with Firebug there will be no doctype declaration (dopesn't matter whether you have switched to source and back earlier). This is only Firefox issue. All other browsers show doctype.

These may be browser issues but

3. If you click on preview page (after setting XHTML1.1) - you are not able to save it in Chrome and Opera
4. In Firefox you are able to save page from preview but with no doctype (doesn't matter whether you have switched to source and back earlier)
5. In Chrome and Opera - you are not able to see source of the preview page
6. In Firefox when you click show source of preview page you get only JavaScript code.

Problem can be reproduced in both CKEditor 3.x and 4.x from CKEditor 3.6.