Opera/safari : we can't copy content when the first paragraph/div in the content is read only.

[Satya Minnekanti]

To reproduce the defect:

1. Copy the following code and paste it in to editor.

<p contenteditable="false">
	first non editable paragraph.</p>
<p>
	first editable paragraph.</p>
<p contenteditable="false">
	second non editable paragraph.</p>
<p>
	second editable paragraph.</p>

2. Press Ctrl + A to select the entire text.

3. Press enter after last paragraph and press Ctrl + V to paste the copied content in step 2.

Expected Result:

All the paragraphs that we have copied in step 2 should be pasted.

Actual Result:

Nothing is pasted.

same bahaviur happens when we have div's instead of paragraphs.

[Garry Yao]

DUP of #6960.