BUG#18676 In order to coincide with 5.0 mysqld error code after bug#18676, Map the 4009 ndb error code to 157 mysql error code 


mysql-test/r/ndb_autodiscover.result:
  changes ndbd error code 4009 to mysqld error code 157 when no cluster connection
sql/ha_ndbcluster.cc:
  define return codes to ndbcluster_table_exists_in_engine to something useful
sql/handler.cc:
  define return codes to ha_table_exists_in_engine to something useful
sql/sql_plugin.cc:
  Add a comment
sql/sql_table.cc:
  clearly define what happens on create table if exists/not exists/not connected to engine
storage/ndb/src/ndbapi/ndberror.c:
  map 4009 ndb error code to 157 mysqld error code