prepared for using query cache in ndb


ndb/include/ndbapi/NdbIndexScanOperation.hpp:
  added force send interface to scan
ndb/include/ndbapi/NdbResultSet.hpp:
  added force send interface to scan
ndb/include/ndbapi/NdbScanOperation.hpp:
  added force send interface to scan
ndb/src/ndbapi/NdbResultSet.cpp:
  added force send interface to scan
ndb/src/ndbapi/NdbScanOperation.cpp:
  added force send interface to scan