manually manage Konversation::Sound (Phonon::AudioOutput)

when parenting a phonon audiooutput to a qapplication an access to
pulseaudio happens after it was destructed already.
qapplication's ctor first destructs q_global_statics and after that
deletes children. however in the phonon's factory global static all
backend objects (including the root object) are deleted which in turn
will shut down the pulseaudio support. at that point from a phonon
perspective everything is shut down, except qapplication then goes on to
delete its children which then causes headaches.

generally speaking this is a problem all phonon frontend objects have,
except only the audiooutput does things that will trigger a sigsev.
so inside phonon a different workaround needs to be made for some future
release.

the fact that global statics are deleted before children seems wrong
though and perhaps needs addressing within qt.

CCBUG: 293004