0-indexing pieces and blocks instead of 1-indexing.
Light refactoring.

torrent
  -calculate whether a piece is complete or not correctly
  -saving of frequently used values such as blockCount and pieceCount.
  -refactoring
Bug fixes:

Originally, offsets were being asked for in blocks, not bytes.  As a result, all hash checks were failing.
Fixed several bugs that happened when a peer choked us after we requested blocks from them.