NdbApi robustness is improved by making certain combinations
of calls illegal.

Specifically, calls which can implicitly execute operations,
without the usual Blob related handling in execute() are
not allowed when there are user-level Blob operations
requiring this handling defined on the transaction.

A new error code is defined to indicate this problem :
  4558 Pending Blob operations must be executed before this call

New testcase testBlobs -bug27772916 is added to daily-devel--07

Approved by : Priyanka Sangam <priyanka.sangam@oracle.com>