Revision 875819

Fix how  we find existing frames for the purpose of form target= submission.
This fixes file upload for drupal 6/jquery.form --- its submit  was incorrectly
blocked as a popup attempt

As we refactored this method, also use it for window.open, fixing us blocking 
opens to _self along the way.

While testing this, I noticed that we can crash konq if we do window.open 
and one of the frames doesn't yet have a part yet. Added a workaround 
suggested by dfaure for now, as the proper fix is too risky and should be 
done on unstable branch only.

BUG:172073
BUG:102044