sql/ha_ndbcluster.cc:
  Modified next_result to process fetched records cached in NdbApi before asking NDB for more. 
  It should also NoCommit any pending operations before contacting NDB again.
  Added utility function define_read_attrs to set the fields that should be read.
sql/ha_ndbcluster.h:
  Add function define_read_attrs, used to set the fields to read
  Add get_nd_lock_type funciton ,to convert MySQL lock type to NDB lock type
  Always compile filtered scan function even if it's not used yet.
  Add variable ops_pending to keep track of "pending" update/delete operations.