What is a valid key?

[Dustin Sallings]

	I just got a bug report for my client regarding multibyte characters  
within a key.  In order to fix it, I need to know what *should* be  
allowed in a key.

	The protocol document is fairly vague as far as what makes up a key.   
It says some specific characters that *aren't* valid, but seems to  
have been written with an ASCII mindset.

	In the binary protocol, we have a lot of freedom, but that freedom  
doesn't extend to the text protocol.

	Should we constrain keys to ASCII, or force clients to understand  
UTF-8 (or some other specific encoding)?

-- 
Dustin Sallings