[MAJOR] replaced all timeouts with struct timeval

The timeout functions were difficult to manipulate because they were
rounding results to the millisecond. Thus, it was difficult to compare
and to check what expired and what did not. Also, the comparison
functions were heavy with multiplies and divides by 1000. Now, all
timeouts are stored in timevals, reducing the number of operations
for updates and leading to cleaner and more efficient code.
diff --git a/src/haproxy.c b/src/haproxy.c
index a2e335e..0acf75f 100644
--- a/src/haproxy.c
+++ b/src/haproxy.c
@@ -684,17 +684,17 @@
  */
 void run_poll_loop()
 {
-	int next_time;
-	tv_now(&now);
+	struct timeval next;
 
+	tv_now(&now);
 	while (1) {
-		next_time = process_runnable_tasks();
+		process_runnable_tasks(&next);
 
 		/* stop when there's no connection left and we don't allow them anymore */
 		if (!actconn && listeners == 0)
 			break;
 
-		cur_poller.poll(&cur_poller, next_time);
+		cur_poller.poll(&cur_poller, &next);
 	}
 }