* dbus/dbus-marshal.c: (_dbus_marshal_string),
	(_dbus_demarshal_double), (_dbus_demarshal_int32),
	(_dbus_demarshal_uint32), (_dbus_demarshal_string),
	(_dbus_marshal_test):
	* dbus/dbus-marshal.h:
	Add string marshal functions and have the demarshal functions
	return the new position.