Update ciphers -s documentation

=item B<-s>

Only list supported ciphers: those consistent with the security level. This

is the actual cipher list an application will support. If this option is

not used then ciphers excluded by the security level will still be listed.

Only list supported ciphers: those consistent with the security level, and

minimum and maximum protocol version.

This is closer to the actual cipher list an application will support.

This program does not set up support for SRP and so SRP based ciphers will

always be excluded when using this option.

PSK ciphers are not enabled by default and it requires the B<-psk> to enable

them.

It also does not change the default list of supported signature algorithms.

On a server the list of supported ciphers might also exclude other ciphers

depending on the configured certificates and presence of DH parameters.

If this option is not used then all ciphers that match the cipherlist will be

listed.

=item B<-psk>