posix: upgrade libevent from 1.4.7 to 1.4.13

third_party/libevent/event-internal.h

 /*
  * Copyright (c) 2000-2004 Niels Provos <provos@citi.umich.edu>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 53 matching lines @@
 
         struct event_list eventqueue;
         struct timeval event_tv;
 
         struct min_heap timeheap;
 
         struct timeval tv_cache;
 };
 
 /* Internal use only: Functions that might be missing from <sys/queue.h> */
-#if !defined(HAVE_TAILQFOREACH) || defined(__QUENTIN_BUILD__)
+#ifndef HAVE_TAILQFOREACH
 #define TAILQ_FIRST(head)               ((head)->tqh_first)
 #define TAILQ_END(head)                 NULL
 #define TAILQ_NEXT(elm, field)          ((elm)->field.tqe_next)
 #define TAILQ_FOREACH(var, head, field)                                 \
         for((var) = TAILQ_FIRST(head);                                  \
             (var) != TAILQ_END(head);                                   \
             (var) = TAILQ_NEXT(var, field))
 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do {                   \
         (elm)->field.tqe_prev = (listelm)->field.tqe_prev;              \
         (elm)->field.tqe_next = (listelm);                              \
         *(listelm)->field.tqe_prev = (elm);                             \
         (listelm)->field.tqe_prev = &(elm)->field.tqe_next;             \
 } while (0)
-#define TAILQ_LAST(head, headname) \
-        (*(((struct headname *)((head)->tqh_last))->tqh_last))
-#define TAILQ_EMPTY(head)       ((head)->tqh_first == NULL)
 #endif /* TAILQ_FOREACH */
 
 int _evsignal_set_handler(struct event_base *base, int evsignal,
                           void (*fn)(int));
 int _evsignal_restore_handler(struct event_base *base, int evsignal);
 
+/* defined in evutil.c */
+const char *evutil_getenv(const char *varname);
+
 #ifdef __cplusplus
 }
 #endif
 
 #endif /* _EVENT_INTERNAL_H_ */