ITS#9322 - Update recommended dependency verions

Update OpenSSL to recommend 1.1.1 series or later (1.0.2+ required)
Update GnuTLS to recommend 3.6.0 series or later (3.3.6+ required)
Update Cyrus-SASL to recommend 2.1.27 or later
Remove Kerberos section, since we no longer directly link to the krb5 libraries
Add section for LDAP load balancing proxy engine