* hans/ssh/codenomicon_degradation/OTP-12784:
  ssh: update ssh version
  ssh: Plain text message returned for invalid version exchange
  ssh: Implement keyboard_interactive on server side
  ssh: Check e and f parameters in kexdh
  ssh: Set max num algoritms in msg_kexinit negotiation

This is how OpenSSH does. The bytes returned will be put on the
user's tty, so it is better with text than a ssh_msg_disconnect

rfc 4253 says in section 8 that:
   "Values of 'e' or 'f' that are not in the range [1, p-1] MUST NOT be
     sent or accepted by either side.  If this condition is violated, the
     key exchange fails."

This commit implements the reception check.

This is to prevent some dos-attac scenarios.  The limit is hard-coded.

If something bad happens and the socket is closed the
call inet:getopts(Socket, [recbuf]) may return {ok, []}. We
want to treat this as a fatal error and terminate gracefully.
The same goes for the case that inet:getopts returns {error, Reason}
that was not handled either.

A fun could be given in the options that will be called whenever
the SSH_MSG_DEBUG message arrives.  This enables the user to
format the printout or just discard it.

The default is changed to not print the message. In RFC4253
printing is a SHOULD, but our new default is to protect logs
from dos attacs.

For limiting Banner Grabbing attempts.