Move our own getopt() implementation to _PyOS_GetOpt(), and use it regardless of whether the system getopt() does what we want. This avoids the hassle with prototypes and externs, and the check to see if the system getopt() does what we want. Prefix optind, optarg and opterr with _PyOS_ to avoid name clashes. Add new include file to define the right symbols. Fix Demo/pyserv/pyserv.c to include getopt.h itself, instead of relying on Python to provide it.