Re: mcp-negotiate-can

[Erik Ostrom <eostrom@research.att.com>]

> 1.	It supports the message syntax (i.e. the BNF) in the MCP 2.1 specificat
> ion
> 2.	It supports the mcp-negotiate-can message with the protocol:, min-versi
> on:, and max-version: keywords

The reason I wanted 'negotiate' to be its own protocol is so that we could
create a new version of the negotiate protocol without creating a new version
of the spec.  This might have been a bad idea, or it might be the wrong way
to handle it.  But that was the rationale.

I would sort of like to require that the mcp-negotiate version is sent, rather
than simply assume that version 2.0 is spoken unless we hear otherwise.  But,
well, we have to assume that anyway, or else we can't have any communication.

But (to reiterate), I'd like to be able to advance the negotiate protocol
independently of the rest of the spec.