Consumer now exits with CLS.

- Consumer now sends a CLS before closing. We tell Master to tell the connections to ignore the quit event. Instead, the consumer does a broadcast of CLS to all connections, waits for the responses, and then sets a "force quit" event which the connection read-write loops -must- listen for. Since the connection-audit loop has already terminated by this time, no new connections will be made.
- Moved all remaining annotated constant values to config modules.
- Refactored code to be a little more intuitive.
The client now dies when all servers go away.

- Fixed bug where we can't get __str__() for a connection with a broken socket.
- A quit signal now interrupts connection-attempts.
- Master now exposes an is_alive property so the end-user can know whether they're still in business.
- We now expose an existing instance of a ConnectionElection object to the message-handler.
- Debugged mpub() command.
Producer now terminates properly on startup problems.

- The connection audit loop that runs at startup now makes sure that none of the greenlets have exceptions, and does several different checks to render a corresponding error message.
- Exceptions emitted during connection now have messages.
- Removed TODOs.