misc: remove ring references

CMakeLists.txt

cmake/GitRevision.cmake

po/POTFILES.in

po/ring-client-gnome.pot

src/accountcreationwizard.cpp

src/accountmigrationview.cpp

src/avatarmanipulation.cpp

src/client.cpp

src/client.h

src/client_options.c

src/client_options.h

src/config.h.in

src/currentcallview.cpp

src/dialogs.c

src/dialogs.h

src/generalsettingsview.cpp

src/generalsettingsview.h

src/main.cpp

src/mainwindow.cpp

src/mainwindow.h