* dbus/dbus-protocol.h: Move various bus service #defines such
	  as DBUS_SERVICE_DBUS and DBUS_NAME_FLAG_PROHIBIT_REPLACEMENT to
	  dbus/dbus-shared.h.
	* dbus/dbus-shared.h: Various defines moved here.
	* dbus/dbus-marshal-header.c: Include dbus-shared.h.