function that deprecates the curl_multi_socket() function. Using the new
function the application tell libcurl what action that was found in the
socket that it passes in. This gives a significant performance boost as it
allows libcurl to avoid a call to poll()/select() for every call to
curl_multi_socket*().
cleanups of this man page. The lengthy description has now also been removed
from curl/multi.h since it immediately got tedious to maintain the info on
two places when I did major updates...
