[IE] Content document scrolls upon focus restored

[Garry Yao]

1. Load enough content to overflow the edit area;
2. Scrolls down to the bottom;
3. Make a text selection in the viewport;
4. Click outside of the editor to blur it;
5. Tab key to bring the focus back to it

• Actual: Editor has focused, content is scrolled by to the top;
• Expected: Editor gain focus with the content scroll bar positon remains.

[Garry Yao]

​http://ckeditor.t/tt/8861/1.html

[Jakub Ś]

Reproducible from CKEditor 3.0 in all versions of IE.

[Jakub Ś]

Reproducible in all IE's in CKEditor 4.x.