HQ / bridging improvements

[matthijskooijman]

This is an overview issue for all things related to improving the HQ connection and bridging, to have a place to discuss overall design and ideas.

Related issues and pull requests are #147, #132, #146, #137, #131.

Some things we should make possible:

• Accept commands / HQ protocol from an arbitrary TCP connection (either make the scout listen on a port, or open a client connection).
• Let HQ, or any other terminal (pinoccio node program, iOS app) receive all print output (even when not in response to a command).
• Let non-HQ terminals receive reports
• Let HQ and all terminals opt-in or opt-out for (custom) reports
• Support multiple lead scouts / multiple routes to HQ

[matthijskooijman]

While writing the above, I realized that we might need some terminology for HQ-like destinations like the iOS app and the node client (terminals?). These can be an endpoint by themselves, but also serve as a bridge to HQ. Would it make sense to have multiple HQ-like things (Pinoccio HQ as well as a custom HQ server)?

[Haifisch]

Consider "Bouncers"? They handle the connection between Pinoccio and the internetz.