Support networking via relay.widgetry.org in examples

[sr229]

I'm investigating this myself but this seems to be infra in place for this via the websocket example, probably worth investigating if we can use the same relay for networking

[Worldwidebrine]

https://github.com/benjamincburns/websockproxy This is ws://relay.widgetry.org implementation. It also has a rate limiting feature for preventing abuse. A good public relay service. I hope c2w to support it too.

But I must notice you that it's in Python2.

[maceip]

the gold standard is websockify, which is a generic websocket -> tcp proxy, which @ktock already implemented in his -net proxy.

What further do these things provide?