维护注意事项:
原vi.c文件中的 strtoul strdup strndup malloc realloc free zalloc需要加vi_前缀.
optind变量需要改为options.optind

暂时跳过同步的commits:
https://github.com/mirror/busybox/commit/f07772f19e29cf44a14c108935afb5668e38fac3
https://github.com/mirror/busybox/commit/f9217cd235c2a139ae22cf549c7614724f1fc6cf
