* dbus/dbus-sysdeps.c (_dbus_set_fd_nonblocking): move to this
	file

	* dbus/dbus-errors.c (dbus_set_error, dbus_set_error_const): allow
	NULL argument for "message" if the error is a well-known one,
	fill in a generic message in this case.

	* dbus/dbus-errors.h (DBusResultCode): Kill DBusResultCode in
	favor of DBusError

	* bus/test.c (bus_test_flush_bus): add

	* bus/policy.c (bus_policy_test): test code stub