so GetPos cannot be used safely, so pass down the known index
of the redline and propogate it everywhere the redline goes

This reverts

commit 36e158ce
Author: Caolán McNamara <caolanm@redhat.com>
Date:   Mon Jan 19 12:09:17 2015 +0000

    if we change the keys we have to resort based on the new keys

which tried to keep the table sorted, but thats no use because
DocumentRedlineManager::SetRedlineMode loops over by index
so sorting the table during the process busts that.

Taking a copy of the entries and looping over that shows another
gadzillion problems.

So try this approach instead.

I imagine it should be possible to calculate the correct
current index of pRedl in DocumentRedlineManager::AppendRedline
but for now assume that we are sorted correctly at that
point and can use GetPos

Change-Id: If092dce185e3b36fd256db390132358cba155847