curl_global_init.3: expand on the SSL and WIN32 bits purpose

\fBCURL_GLOBAL_ACK_EINTR\fP.

.TP

.B CURL_GLOBAL_SSL

Initialize SSL

Initialize SSL.

The implication here is that if this bit is not set, the initialization of the

SSL layer needs to be done by the application or at least outside of

libcurl. The exact procedure how to do SSL initializtion depends on the TLS

backend libcurl uses.

Doing TLS based transfers without having the TLS layer initialized may lead to

unexpected behaviors.

.TP

.B CURL_GLOBAL_WIN32

Initialize the Win32 socket libraries.

The implication here is that if this bit is not set, the initialization of

winsock has to be done by the application or you risk getting undefined

behaviors. This option exists for when the initialization is handled outside

of libcurl so there's no need for libcurl to do it again.

.TP

.B CURL_GLOBAL_NOTHING

Initialise nothing extra. This sets no bit.