posix: upgrade libevent from 1.4.7 to 1.4.13

third_party/libevent/evutil.h

 /*
  * Copyright (c) 2007 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 150 matching lines @@
 #endif
 
 
 /* big-int related functions */
 ev_int64_t evutil_strtoll(const char *s, char **endptr, int base);
 
 
 #ifdef _EVENT_HAVE_GETTIMEOFDAY
 #define evutil_gettimeofday(tv, tz) gettimeofday((tv), (tz))
 #else
+struct timezone;
 int evutil_gettimeofday(struct timeval *tv, struct timezone *tz);
 #endif
 
 int evutil_snprintf(char *buf, size_t buflen, const char *format, ...)
 #ifdef __GNUC__
         __attribute__((format(printf, 3, 4)))
 #endif
         ;
 int evutil_vsnprintf(char *buf, size_t buflen, const char *format, va_list ap);
 
 #ifdef __cplusplus
 }
 #endif
 
 #endif /* _EVUTIL_H_ */