ssh client - supported host keys need to be sorted

[samrushing]

When we send kexinit to the server, we give it a list of supported host key types. If we have e.g. an RSA key in our known_hosts file, but do not place RSA at the front of the list, then we'll get an Invalid_Server_Public_host_Key because the server always offers DSS first. (apparently there's no retry?)

[samrushing]

My evidence for this theory is in the output from -v -v -v:

debug3: order_hostkeyalgs: prefer hostkeyalgs: [email protected],[email protected],ssh-rsa