mcp-negotiate-can

["Christopher A. Rath" <car@research.att.com>]

I would like to propose the elimination of mcp-negotiate as a protocol in itself.  The current spec states that a client can assume at least an MCP 2.0 implementation of the negotiate protocol if the server supports mcp 2.1.  Since the negotiation of protocols is critical to getting messaging started at all, I would like to remove this fuzziness.  Rather than making assumptions about a server's capabilities, the initial mcp message with its version numbers should also imply something about the negotiate protocol.

In simple terms, then, I propose that the mcp and mcp-negotiate-can messages are both part of the "MCP" protocol.  If a server states support of version 2.1 of mcp, then:

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

Christopher A. Rath
car@research.att.com