multi: don't expire timeouts at disonnect or done

The functions Curl_disconnect() and Curl_done() are both used within the
scope of a single request so they cannot be allowed to use
Curl_expire(... 0) to kill all timeouts as there are some timeouts that
are set before a request that are supposed to remain until the request
is done.

The timeouts are now instead cleared at curl_easy_cleanup() and when the
multi state machine changes a handle to the complete state.

lib/multi.c

@@ -1594,6 +1594,8 @@ static CURLMcode multi_runsingle(struct Curl_multi *multi,
       /* Important: reset the conn pointer so that we don't point to memory
          that could be freed anytime */
       easy->easy_conn = NULL;
+
+      Curl_expire(data, 0); /* stop all timers */
       break;
 
     case CURLM_STATE_MSGSENT:

lib/url.c

@@ -481,6 +481,8 @@ CURLcode Curl_close(struct SessionHandle *data)
   }
 #endif
 
+  Curl_expire(data, 0); /* shut off timers */
+
   if(m)
     /* This handle is still part of a multi handle, take care of this first
        and detach this handle from there. */
@@ -2579,7 +2581,6 @@ CURLcode Curl_disconnect(struct connectdata *conn)
                   NULL, Curl_scan_cache_used);
 #endif
 
-  Curl_expire(data, 0); /* shut off timers */
   Curl_hostcache_prune(data); /* kill old DNS cache entries */
 
   {
@@ -5131,8 +5132,6 @@ CURLcode Curl_done(struct connectdata **connp,
   conn = *connp;
   data = conn->data;
 
-  Curl_expire(data, 0); /* stop timer */
-
   if(conn->bits.done)
     /* Stop if Curl_done() has already been called */
     return CURLE_OK;