WL#1730: Handler: "rollback" to last statement

It should be possible to "rollback" the last statement part of a transaction.
Ex:
 START TRANSACTION;
 INSERT INTO T1 VALUES(1,2), (2,3);
 UPDATE T1 SET b=2 WHERE b=3; << error occurs, inserts should not dissapear.

 UPDATE T1 set b=7 WHERE b=3;
 COMMIT;

  Investigate how this works using the NDB table handler.

Probably dependent on wl 1355 - rollback savepoint