bug: check if storage engine is enabled to avoif code dump


BitKeeper/etc/ignore:
  Added storage/ndb/test/ndbapi/DbAsyncGenerator storage/ndb/test/ndbapi/DbCreate storage/ndb/test/ndbapi/ndbapi_slow_select storage/ndb/test/ndbapi/testBitfield storage/ndb/test/ndbapi/testLcp storage/ndb/test/ndbapi/testPartitioning storage/ndb/test/ndbapi/testReadPerf storage/ndb/test/ndbapi/test_event_merge storage/ndb/test/tools/listen_event to the ignore list