Quiz using popup window with JavaScript secuity, not possibel to use Atto text formatting tools

This follows from MDL-46088, where we made Atto basically work.

Now we have the problem that you can't reliably select text and apply formatting in a range of browsers.

From abgreeve's testing there:

{blockquote}
With a bit more testing I found that browsers under windows had some unexpected problems.


IE10: I can click in the text area, but I can not highlight anything.
Using the keyboard I can highlight something, but trying to implement some formatting results in the one area being affected only, and attempts to use any sort of text formatting elsewhere will not work.

Chrome: Highlighting in the text area works, but similar problems to highlighting and formatting in IE are present.

Firefox: The same problems as Chrome.

edit I don't know what I was doing before, but I can see that this behaviour is actually on all operating systems.{blockquote}