Leverage IPFS nodes for download

[lidel]

Downloading from dist.ipfs.io may fail due to routing or service issues.
It does not leverage the fact that data could be downloaded from a local IPFS node, or alternative gateway.

Switching download logic to something like ipfs-or-gateway should mitigate issues described in https://github.com/ipfs/npm-go-ipfs-dep/issues/37, where our gateway broke CI for various projects.

The idea

• introduce an implicit (but configurable) list of gateways to try
• try downloading from each of them, in order, and fail only when all of them fail
• default list should work for most of people: [default local, default public]
  • try local IPFS gateway first (default: http://127.0.0.1:8080/ipns/dist.ipfs.io)
  • if that fails, fallback to a public one (default: https://ipfs.io/ipns/dist.ipfs.io)
• allow people to provide their own list (to use own nodes, or trusted public ones such as cloudflare)

@aphelionz would that help?

[aphelionz]

Seems good, let's give it a shot!