Users can fetch files from other peers

[holmesworcester]

Downloading files from one peer isn't desirable.

Options:

0. Roll our own p2p network, i.e. peers message the channel asking who has the files they want and download from the first person who responds, and perhaps peers respond when download is complete as well.
1. Host files encrypted and named with their hash, on separate global IPFS network that everyone is on, like the master channel, and all clients try to download them and "seed".
2. Host files on an IPFS network working over the set of peers for a channel.
3. Use some torrent-like library, or roll our own (e.g. option 0 but breaking files into parts)