DOCS: Updated CURLOPT_CONNECT_ONLY to reflect usage in other protocols

.IP CURLOPT_CONNECT_ONLY

Pass a long. If the parameter equals 1, it tells the library to perform all

the required proxy authentication and connection setup, but no data transfer.

This option is useful only on HTTP URLs.

This option is implemented for HTTP, SMTP and POP3.

This option is useful with the \fICURLINFO_LASTSOCKET\fP option to

\fIcurl_easy_getinfo(3)\fP. The library can set up the connection and then the

application can obtain the most recently used socket for special data

The option can be used to simply test a connection to a server, but is more

useful when used with the \fICURLINFO_LASTSOCKET\fP option to

\fIcurl_easy_getinfo(3)\fP as the library can set up the connection and then

the application can obtain the most recently used socket for special data

transfers. (Added in 7.15.2)

.IP CURLOPT_USE_SSL

Pass a long using one of the values from below, to make libcurl use your