[crossfire] Crossfire protocol cleanup

[Nicolas Weeger (Laposte)]

> It has been noted that within both the client and server, there is a fair
> amount of old code around to support older versions of the servers and
> older versions of the client.  The setup command has also gotten a lot of
> options with methods to negotiate what protocol commands it supports, and
> directly related to that, there is a lot of code in the server that
> does/does not do something based on what has been negotiated.
>
>   The idea here is to clean all that up for 2.0.  Specifically:

<snip/snip>

I agree code cleanup could and should be done, including removal of old and 
deprecated things.

I also support Brendan's idea to have an intermediate release with still the 
setup command for 2.0 stuff, so there could be an intermediate release.

We could simply remove the arguments of the setup command, and keep it for new 
(post 2.0) things.

Nicolas