move libevent into base

base/third_party/libevent/evport.c

 /*
  * Submitted by David Pacheco (dp.spambait@gmail.com)
  *
  * 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 499 matching lines @@
         struct evport_data *evpd = arg;
 
         evsignal_dealloc(base);
 
         close(evpd->ed_port);
 
         if (evpd->ed_fds)
                 free(evpd->ed_fds);
         free(evpd);
 }