Add sys.excepthook. Update docstring and library reference section on 'sys' module. New API PyErr_Display, just for displaying errors, called by excepthook. Uncaught exceptions now call sys.excepthook; if that fails, we fall back to calling PyErr_Display directly. Also comes with sys.__excepthook__ and sys.__displayhook__.

#include "Python.h"

#ifndef PLATFORM
#define PLATFORM "unknown"
#endif

const char *
Py_GetPlatform(void)
{
	return PLATFORM;
}