Move gateway to ipfs.io

[jbenet]

We want to have the gateways at ipfs.io instead of gateway.ipfs.io

This requires

• IPNS proved robust enough for ipfs.io website.
• faster gc on the gateways
• period reboot on the gateways (clear any bad states, etc)

[ghost]

IPNS proved robust enough for ipfs.io website

This isn't neccessarily a dependency. We can easily point ipfs.io/ipfs and ipfs.io/ipns to the port 8080.

[jbenet]

@lgierth yeah, we could either:

1. use nginx rewriting to redirect / --> /ipfs/<root-hash-of-ipfs-website> so it gets hosted by ipfs.
2. host https://github.com/ipfs/website directly from nginx as a backup

[jbenet]

it may be nice to make (1.) possible from within go-ipfs itself. So we could:

ipfs config Gateway.HttpRoot <root-hash-of-ipfs-website>

and have

curl http://<host>/foo/bar

use

/ipfs/<root-hash-of-ipfs-website>/foo/bar

but it may be pulling in the kitchen sink

[ghost]

Remaining steps:

• get additional SSL certs for ipfs.io and dogfeed.ipfs.io
• use SSL SNI to pick ipfs.io/gateway/dogfeed cert
• make /ipfs and /ipns work with self-hosted ipfs.io -- Make /ipfs and /ipns work with self-hosted ipfs.io #72
• for arbitrary pages:
  • embed directory-listing styles -- gateway: embed directory-listing styles kubo#1615
  • catch-all ssl vhost with return 444, to refuse handshakes for anything that we don't have a cert for

[jbenet]