#6109: Implement stop recorded file playback signal

sflphone-client-gnome/src/actions.c

sflphone-client-gnome/src/callable_obj.c

sflphone-client-gnome/src/conference_obj.c

sflphone-client-gnome/src/contacts/conferencelist.c

sflphone-client-gnome/src/dbus/callmanager-introspec.xml

sflphone-client-gnome/src/dbus/dbus.c

sflphone-common/src/audio/sound/audiofile.cpp

sflphone-common/src/audio/sound/audiofile.h

sflphone-common/src/dbus/callmanager-introspec.xml

sflphone-common/src/managerimpl.cpp