* testing of execution of UNDO_ROW_UPDATE
* when executing an UNDO_ROW_UPDATE, store "UNDO_ROW_UPDATE" as
"type of undone record" into the CLR_END record.


storage/maria/ma_blockrec.c:
  When logging a CLR_END in write_block_record(), it can be for
  a DELETE or for an UPDATE (now that Monty has coded execution of
  UNDO_UPDATE)
storage/maria/ma_loghandler.c:
  UNDO_ROW_UPDATE's execution coded, so no crash
storage/maria/ma_recovery.c:
  UNDO_ROW_UPDATE's execution now coded, so no crash
storage/maria/ma_test1.c:
  upper case letter
storage/maria/ma_test_recovery.expected:
  output of testing execution of UNDO_ROW_UPDATE. Table's checksum
  not recovered (known issue not specific to UPDATE).
storage/maria/ma_test_recovery:
  Test execution of UNDO_ROW_UPDATE: first we stop ma_test1 after
  deletes and commit, then we stop ma_test1 after updates and abort;
  we verify that updates are rolled back by comparing tables