protocol auto-discovery

[Dustin Sallings]

	I just committed the protocol autodiscovery stuff into the binary  
tree.  The -B option is gone, so just connect to the thing and say  
what you've got to say.

	I considered having it negotiate per-command.  If someone else really  
wants to be able to send multiple commands in different protocols on  
the same connection, it's possible, but pipelining will make you a bit  
unhappy.

	The negotiation isn't free, and is slightly ugly (I read 1 byte and  
then shove it into the appropriate protocol-specific location).  The  
nread and command read buffer handling is a bit too different at the  
moment to do anything much better.  I figured it doesn't matter too  
much at the moment.

	Note that it's theoretically possible to pin the server to one  
protocol or the other and avoid negotiation.

	I tested this by running my java client test through it.  That test  
both protocols over ipv4 and ipv6 with lots of pipelining and other  
such nonsense.  You would be a fool to not deploy this to production  
immediately.

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Dustin Sallings