Switch from using 'nacl_main' to 'main' entry point

ports/ipython-ppapi/kernel.cc

-/* Copyright (c) 2014 Google Inc. All rights reserved.
+/* Copyright (c) 2014 The Native Client Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file. */
 
 #include <python2.7/Python.h>
 #include <libtar.h>
 #include <locale.h>
 #include <stdio.h>
 #include <fcntl.h>
 #include <sys/mount.h>
 #include <errno.h>
 
 #include "ppapi/cpp/var.h"
 #include "ppapi/cpp/var_array.h"
 #include "ppapi/cpp/var_dictionary.h"
 #include "ppapi_simple/ps_interface.h"
 
 #include "nacl_io/nacl_io.h"
-#include "ppapi_simple/ps_main.h"
 #include "ppapi_simple/ps_instance.h"
 
 #ifdef __pnacl__
 #define DATA_FILE "pydata_pnacl.tar"
 #else
 #error "Unknown arch"
 #endif
 
 /* TODO(bradnelson): Switch ipython to use cli_main and drop this. */
 
@@ skipping 108 matching lines @@
     "Post a message encoded as JSON"
   },
   {
     "_AcquireJSONMessageWait",
     acquire_json_message_wait,
     METH_VARARGS,
     "Acquire a message encoded as JSON (blocking)"},
   {NULL, NULL, 0, NULL}
 };
 
-int ipython_kernel_main(int argc, char **argv) {
+int main(int argc, char **argv) {
   printf("Setting up unix environment...\n");
   if (setup_unix_environment()) {
     printf("Error: %s\n", strerror(errno));
     return -1;
   }
   printf("done\n");
 
   // Initialize Pepper API
   PSInterfaceInit();
 
@@ skipping 15 matching lines @@
       return -1;
     }
 
     quit = PyRun_SimpleFileEx(main, main_filename, 1);
 
     Py_Finalize();
   }
 
   return 0;
 }
-
-PPAPI_SIMPLE_REGISTER_MAIN(ipython_kernel_main)