name directory: allow unicode names

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

bin/dbus/dbusconfigurationmanager.hpp

bin/jni/configurationmanager.i

bin/jni/jni_interface.i

bin/nodejs/callback.h

bin/nodejs/configurationmanager.i

bin/nodejs/nodejs_interface.i

src/client/configurationmanager.cpp

src/jami/configurationmanager_interface.h

src/jamidht/jamiaccount.cpp

src/jamidht/namedirectory.cpp

src/jamidht/namedirectory.h

src/string_utils.cpp

src/string_utils.h

test/unitTest/namedirectory/namedirectory.cpp