Enter mode for shift+enter incorrect

[Szymon Cofalik]

Steps to reproduce:

1. Initialize CKEDITOR with those options:

   CKEDITOR.replace( 'editor1', {
   	extraPlugins: 'enterkey',
   	enterMode: CKEDITOR.ENTER_P,
   	shiftEnterMode: CKEDITOR.ENTER_DIV
   });
   

2. Write some text in the editor then try to break it with shift+enter.

Result: <p> has been inserted.
Expected result: <div> has been inserted.

The same bug occurs when you set

	enterMode: CKEDITOR.ENTER_DIV,
	shiftEnterMode: CKEDITOR.ENTER_P

Then <div> is inserted instead of <p>. It works fine only if one of options is CKEDITOR.ENTER_BR

You can test this on sample samples/plugins/enterkey/enterkey.html