[misc.c misc.h sshd.8 sshconnect.c]
     Add port identifier to known_hosts for non-default ports, based originally
     on a patch from Devin Nate in bz#910.
     For any connection using the default port or using a HostKeyAlias the
     format is unchanged, otherwise the host name or address is enclosed
     within square brackets in the same format as sshd's ListenAddress.
     Tested by many, ok markus@.