Ellipses were used to express that the '-rand' value can specify
multiple files, like this:

    B<-rand> I<file...>

Because there are conventions around ellipses, this becomes confusing,
because '-rand file...' is normally intepreted to mean that
'-rand file1 file2 file3' would be processed as three randomness
files, which makes no sense.

Rather than making things complicated with more elaborate syntax, we
change it to:

    B<-rand> I<files>

… dash

Quite a lot of replacables were still bold, and some options were
mentioned without a beginning dash.

Almost all OpenSSL commands are in reality 'openssl cmd', so make sure
they are refered to like that and not just as the sub-command.

Self-references are avoided as much as is possible, and replaced with
"this command".  In some cases, we even avoid that with a slight
rewrite of the sentence or paragrah they were in.  However, in the few
cases where a self-reference is still admissible, they are done in
bold, i.e. openssl-speed.pod references itself like this:

    B<openssl speed>

References to other commands are done as manual links, i.e. CA.pl.pod
references 'openssl req' like this: L<openssl-req(1)>

Some commands are examples rather than references; we enclose those in
C<>.

While we are it, we abolish "utility", replacing it with "command", or
remove it entirely in some cases.

"gost" was called "ccgost".
"rsax" was treated like literal input rather than an engine name.

Better synopsis for 'openssl dgst' and 'openssl enc', correct names
for 'openssl rehash' ('c_rehash' is mentioned there too), correct
option end marker for 'openssl verify', and finally, refer to
sub-commands as sub-commands.

Make replacables italic, change '-rand' to '-r', fix links.

Normalise on L<openssl-cmd(1)> over L<cmd(1)>

It's a separate script, not an openssl sub-command

… with a dash

… with a dash