RAISE now can re-throw exception

Up to now the statement RAISE did have syntax as: 
     raise errNumber [, errMsg]

Now it is 
     raise [errNumber [, errMsg]]

Except syntax also is implemented additional logic:
     raise without parameters means throw the same exception forward.

BEGIN
INSERT INTO t1 VALUES(1);
INSERT INTO t1 VALUES(1);
EXCEPTION
WHEN 23503 THEN
PRINT 'Unique violation'
RAISE;
END;