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* Upgrade Gliderlabs SSH to 0.3.3 and add FailedConnectionCallback

Following the merging of https://github.com/gliderlabs/ssh/pull/143

 we
can now report connections to the ssh server that have failed before
public key exchange has completed using the standard fail2ban message.

This PR updates Gliderlabs SSH and adds a callback that will provide this
logging.
Signed-off-by: Andrew Thornton <art27@cantab.net>

* move the callback to its own function to make the logging appear little nicer
Signed-off-by: Andrew Thornton <art27@cantab.net>