Network

We've written a simple client-server program where many clients can connect to a single server.

```
    C
    |
C - S - C
    |
    C
```

However, raft needs a set of servers to communicate with one another. 

```
S - S
| X |
S - S
```

This implements just that. 

Run `raft bind_adress [connect_address]...` on multiple machines to see it in action. For example, you could run

    raft 127.0.0.1:8000 127.0.0.1:8001

on one machine and

    raft 127.0.0.1:8001 127.0.0.1:8000

on another. The two machines will start talking to one another.

The next step for raft is to figure out capnp-proto's RPC's. Then, we'll plug in RPC's to this many-to-many communication to implement leader election.