Log Message:
Update leveldb to version 1.14.0. Major changes:

Release LevelDB 1.14

    Fix issues 200, 201

    Also,
    * Fix link to bigtable paper in docs.
    * New sstables will have the file extension .ldb. .sst files will
      continue to be recognized.
    * When building for iOS, use xcrun to execute the compiler. This may
      affect issue 177.

LevelDB 1.13

    Fix issues 77, 87, 182, 190.

    Additionally, fix the bug described in
    https://groups.google.com/d/msg/leveldb/yL6h1mAOc20/vLU64RylIdMJ
    where a large contiguous keyspace of deleted data was not getting
    compacted.

    Also fix a bug where options.max_open_files was not getting clamped
    properly.