swarm: add conversation member event signal

bin/dbus/cx.ring.Ring.ConfigurationManager.xml

bin/dbus/dbusclient.cpp

bin/jni/conversation.i

bin/jni/jni_interface.i

bin/nodejs/conversation.i

src/client/ring_signal.cpp

src/dring/conversation_interface.h

src/gittransport.cpp

src/ice_transport.cpp

src/jamidht/channeled_transfers.cpp

src/jamidht/connectionmanager.cpp

src/jamidht/conversationrepository.cpp

src/jamidht/jamiaccount.cpp

src/jamidht/jamiaccount.h

src/manager.cpp

test/unitTest/conversation/conversation.cpp