[IE8] Crash when widget copy & paste

[Olek Nowodziński]

I spotted some crashes when running tests in IE8. For example, the crashing test is "test pasting widget which was copied (d&d) when its nested editable was focused" in dt/plugins/widget/nestededitables.html

It doesn't matter whether that test is standalone or ran along with others.

Also there's manual TC (major):

1. Open ​http://ckeditor4.t/ckeditor/plugins/image2/samples/image2.html
2. Focus the widget.
3. C-c
4. Without changing/touching anything C-v
5. Crash.

See attached video.

IE version: 8.0.6001 (VM from ModernIE).