Fixed NbtWriter.WriteByteArray(String,Stream,int,byte[]) being too picky with buffers, unnecessarily limiting it to NbtBinaryWriter.MaxWriteChunk (512 MiB). The limit has been removed.
Fixed NbtList.IndexOf(null) throwing ArgumentNullException instead of returning a negative value.
Expanded unit test coverage slightly, including recently-fixed NbtWriter.WriteByteArray and NbtList.IndexOf. Now at 97% (and unlikely to change much)