Expected new features

• Hierarchical directory structure in tar file system #10
• Fix issues in index file format #9
• long file name issue #1
• Asynchronous write of index #11
• Index related performance and memory numbers.
  • How much time to create index
  • How much time to write index to storage
  • How much time to read index from storage
  • How much memory is taken by index
  • How much storage is taken by index