Prior to this change when no file descriptors were ready on platforms
other than Windows the multi examples would sleep whatever was in
timeout, which may or may not have been less than the minimum
recommended value [1] of 100ms.
[1]: http://curl.haxx.se/libcurl/c/curl_multi_fdset.html
Windows does not support using select() for sleeping without a dummy
socket. Instead use Windows' Sleep() and sleep for 100ms which is the
minimum suggested value in the curl_multi_fdset() doc.
Prior to this change the multi examples would exit prematurely since
select() would error instead of sleeping when called without an fd.
Reported-by: Johan Lantz
Bug: http://curl.haxx.se/mail/lib-2014-11/0221.html
all multi and hiper examples:
* don't loop curl_multi_perform calls, that was <7.20.0 style, currently
the exported multi functions will not return CURLM_CALL_MULTI_PERFORM
all hiper examples:
* renamed check_run_count to check_multi_info
* don't compare current running handle count with previous value, this
was the wrong way to check for finished requests, simply call
curl_multi_info_read
* it's also safe to call curl_multi_remove_handle inside the
curl_multi_info_read loop.
ghiper.c:
* replaced curl_multi_socket (that function is marked as obsolete) calls
with curl_multi_socket_action calls (as in hiperfifo.c and
evhiperfifo.c)
ghiper.c and evhiperfifo.c:
* be smart as hiperfifo.c, don't do uncessary curl_multi_* calls in
new_conn and main
