Bug 5093: List http_port params that https_port/ftp_port lack (#1977)

Bug 5093: List http_port params that https_port/ftp_port lack (#1977)

To avoid documentation duplication, current https_port and ftp_port
directive descriptions reference http_port directive instead of
detailing their own supported parameters. For https_port, this solution
creates a false impression that the directive supports all http_port
options. Our ftp_port documentation is better but still leaves the
reader guessing which options are actually supported.

This change starts enumerating http_port configuration parameters that
ftp_port and https_port directives do _not_ support. Eventually, Squid
should reject configurations with unsupported listening port options.