enabling "none" cipher

[Stef Bon]

Hi,

I've written also SSH software, and as I see it the "none"
ciphers/hmac/compress algo is the algo used in the phase before new
keys are used (in the init phase).

The send and receive functions are designed to use
ciphers/hmac/compress after they are initialized and setup to use the
new keys. These functions should be robust enough to use the "none"
cipher/hmac/compress algo's just like before the new keys are
determined.

S. Bon