[PATCH-3-6-0] fdo#47368 - many crashes with a11y on OS/X ...

Hi guys,

        Norbert's trace with bugs suggested a great site for the source of
this; an unfortunately outdated copy of listeners that can be emitted
after they are removed. This simple patch uses the list copy for safe
iteration, while checking the parent listener is still registered. At
least, I hope it does ;-)

        kudos to Norbert for managing to reproduce it on a build with symbols.
2x extra reviews much appreciated to take it to -3-6-0:

http://cgit.freedesktop.org/libreoffice/core/commit/?h=libreoffice-3-6&id=222b7032153cfd3a6f5e12e2fc855ccabc2ea769

        Of course, it is -possible- that continuing to emit listener that have
been already removed is required by some dark corner of the code (if so
it is prolly best to find it sooner rather than later).

        Thanks ! :-)

                Michael.

-- 
michael.meeks@suse.com  <><, Pseudo Engineer, itinerant idiot