Magnet URI

Magnet URIs are used with BitTorrent for peer-to-peer file retrieval.

Links

 * https://en.wikipedia.org/wiki/Magnet_URI_scheme
 * http://www.bittorrent.org/beps/bep_0009.html
 * https://stackoverflow.com/questions/3844502/how-do-bittorrent-magnet-links-work

TODO: Summarize above links here.