Import the first cut for manual pages.

They are written in Perl's POD format for two reasons: First Perl is already
needed for SSLeay and second, POD is easy to write and maintain _AND_ created
nice looking NRoff manpages.

The idea is to have three manual pages:

  openssl(1) ... The manpage for the `openssl' program (formerly ssleay)
  crypto(3) .... The manpage for crypto.h/libcrypto.a
  ssl(3) ....... The manpage for ssl.h/libssl.a

The openssl(1) should be very similar to cvs(1), i.e.  it should document all
commands in a compact way.  And I've even created the first cut for an
overview of all 243 functions of the SSL API for ssl.pod. More to come...