Add comment about GNUWin32's cp not having the file system problem.

contrib/pg_standby/pg_standby.c

 /*
- * $PostgreSQL: pgsql/contrib/pg_standby/pg_standby.c,v 1.14 2008/12/15 21:11:54 momjian Exp $ 
+ * $PostgreSQL: pgsql/contrib/pg_standby/pg_standby.c,v 1.15 2008/12/15 21:39:25 momjian Exp $ 
  *
  *
  * pg_standby.c
@@ -183,7 +183,8 @@ CustomizableNextWALFileReady()
 			 * even though the file is still being copied and cannot be opened
 			 * by pg_standby yet. So we wait for sleeptime secs before
 			 * attempting to restore. If that is not enough, we will rely on
-			 * the retry/holdoff mechanism.
+			 * the retry/holdoff mechanism.  GNUWin32's cp does not have
+			 * this problem.
 			 */
 			pg_usleep(sleeptime * 1000000L);
 #endif