/*
Package uiserver creates a server to share an object (readonly) with clients.

Background

We want to deal with a user interface that is output-only: we only care about
providing a representation of the internal state to users, not getting their
input (that is, we'll do that part as a separate component).

We also want the UI to be completely detached from the core, ie running as a
separate process: to do so, bind a socket and exchange informations over it.

This is especially reasonable when dealing with "embedded" boards where the
outputs might be LED or OLED displays and the inputs might be pushbuttons so
privilege separation is especially needed, but can prove useful in any other
context.

It must be easy to write a UI with a different programming language: to do
so, gob is excluded, JSON is preferred.
We assume that the "state" is pretty small, so caring about diffs will only
be a waste of time.

Protocol

Bind a socket. Every UI is a client, which connects to our socket.
Upon connection, send some "hello" just to check versions etcetera. Then
send a serialization of the complete state.  Upon change, just send it all
again.
Conversely, the client will read the socket and set the UI according to the
state that has just been read.

Usage

The uiserver package implements a generic server specifically designed to
send updates upon connection and whenever asked to (with NetUI.Update())
*/
package uiserver