History and log for ZeroNet site files change (a.k.a. Archiving, Versioning)

http://127.0.0.1:43110/Talk.ZeroNetwork.bit/?Topic:1513607828_13aB79mzuRLgDYzQthn9wzycjw77WyDXh6/File+History

If someone change some file, other peers should be easily know **which files changed** and **what the files previous data**.

Start with the linked File History discussion and compare its proposal with the issue’s description of changed files and previous data. The scope, affected entry points, storage model, and tests are not identified in the issue; done would require an agreed design and verification that peers can discover changes and retrieve earlier file data.

索引モデルが issue の本文から書いたものです。