#6109: Implement stop recording playback button

sflphone-client-gnome/src/callable_obj.c

sflphone-client-gnome/src/callable_obj.h

sflphone-client-gnome/src/conference_obj.h

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

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

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

sflphone-client-gnome/src/ui.xml

sflphone-client-gnome/src/uimanager.c

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

sflphone-common/src/dbus/callmanager.cpp

sflphone-common/src/dbus/callmanager.h

sflphone-common/src/managerimpl.cpp

sflphone-common/src/managerimpl.h