from import.c to ssh.h, so that the implementation can see them. This
necessitates ssh.h's including <stdio.h>.
Also remove a spare prototype for base64_encode_atom() from import.c.
[originally from svn r2481]
broken: the OpenSSL EVP layer specifies a very particular form of
padding, which I wasn't generating because it hadn't occurred to me
that it might be mandatory. Irritatingly this was causing our
exported OpenSSH keys to load perfectly happily back in through our
OpenSSH import routines, but to be rejected by OpenSSH proper. Sigh.
[originally from svn r1733]
