Removed inaccurate comment for upcoming curl_multi_socket() and family.

 *

 * Desc:    An alternative version of curl_multi_perform() that allows the

 *          application to pass in one of the file descriptors that have been

 *          detected to have "action" on them and let libcurl perform. This

 *          allows libcurl to not have to scan through all possible file

 *          descriptors to check for this. The app is recommended to pass in

 *          the 'easy' argument (or set it to CURL_EASY_NONE) to make libcurl

 *          figure out the internal structure even faster and easier.  If the

 *          easy argument is set to something else than CURL_EASY_NONE, the

 *          's' (socket) argument will be ignored by libcurl.

 *

 *          It also informs the application about updates in the socket (file

 *          descriptor) status by doing none, one or multiple calls to the

 *          curl_socket_callback. It thus updates the status with changes

 *          since the previous time this function was used. If 'callback' is

 *          NULL, no callback will be called. A status change may also be a

 *          new timeout only, having the same IN/OUT status as before.

 *

 *          If a previous wait for socket action(s) timed out, you should call

 *          this function with the socket argument set to

 *          CURL_SOCKET_TIMEOUT. If you want to force libcurl to (re-)check

 *          all its internal sockets, and call the callback with status for

 *          all sockets no matter what the previous state is, you call

 *          curl_multi_socket_all() instead.

 *

 *          curl_multi_perform() is thus the equivalent of calling

 *          curl_multi_socket_all(handle, NULL, NULL);

 *

 *          IMPLEMENTATION: libcurl will need an internal hash table to map

 *          socket numbers to internal easy handles for the cases when 'easy'

 *          is set to CURL_EASY_NONE.

 *

 *          Regarding the timeout argument in the callback: it is the timeout

 *          (in milliseconds) for waiting on action on this socket (and the

 *          given time period starts when the callback is called) until you

 *          should call curl_multi_socket() with the timeout stuff mentioned

 *          above. If "actions" happens on the socket before the timeout

 *          happens, remember that the timout timer keeps ticking until told

 *          otherwise.

 *

 *          The "what" argument has one of five values:

 *

 *            0 CURL_POLL_NONE (0)   - register, not interested in readiness

 *            1 CURL_POLL_IN         - register, interested in read readiness

 *            2 CURL_POLL_OUT        - register, interested in write readiness

 *            3 CURL_POLL_INOUT      - register, interested in both

 *            4 CURL_POLL_REMOVE     - deregister

 *          detected to have "action" on them and let libcurl perform.

 *          See man page for details.

 */

#define CURL_POLL_NONE   0

#define CURL_POLL_IN     1

typedef int (*curl_socket_callback)(CURL *easy,      /* easy handle */

                                    curl_socket_t s, /* socket */

                                    int what,        /* see above */

                                    long ms,         /* timeout for wait */

                                    void *userp);    /* "private" pointer */

CURLMcode curl_multi_socket(CURLM *multi_handle,