HPCC-11764 Dafilesrv authentication and encryption on transport

Current dafilesrv uses unencrypted sockets which is not secure. This update
adds a new section to the environment.conf file to optionally specify that
dafilesrv and its clients should use SSL, and points to the cert file, key file
and provides an encrypted passphrase. If specified, dafilesrv and its clients
will enable secure sockets (openSSL) and communicate in a secure manner.

Signed-off-by: William Whitehead <william.whitehead@lexisnexis.com>
From what I read you are correct. A caveat is that SSL_pending will always return 0 if you have not already called SSL_read. I will need to do a closer analysis and some testing to make sure this is the case. If so I will remove the call to the base socket class and just return whatever SSL_pending returns to me(ie remove the "if(pending >0"