[#1887] Information about the state of the current SIP call is displayed

sflphone-client-gnome/src/actions.c

sflphone-client-gnome/src/actions.h

sflphone-client-gnome/src/callable_obj.c

sflphone-client-gnome/src/callable_obj.h

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

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

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

sflphone-client-gnome/src/dbus/marshaller.list

sflphone-common/src/audio/audiortp/ZrtpSessionCallback.cpp

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

sflphone-common/src/sip/sipvoiplink.cpp