[wip] Integrate with ubus, rpcd, netifd - unlocks restartless config and network changes

[ghost]

All aboard the ubus to restartless cjdroute!

[ghost]

Reloading passwords already works pretty well. It handles password addition and removal, but not yet changes of an individual password.

On password removal, cjdroute sometimes exits.

[wfleurant]

Many new factors, but is there a hint of what causes the exit?

[kpcyrd]

Yes, we are trying to trace this in cjdelisle/cjdns#687