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__.
diff --git a/Include/pythonrun.h b/Include/pythonrun.h
index c2aa207..e7274ec 100644
--- a/Include/pythonrun.h
+++ b/Include/pythonrun.h
@@ -59,6 +59,7 @@
DL_IMPORT(void) PyErr_Print(void);
DL_IMPORT(void) PyErr_PrintEx(int);
+DL_IMPORT(void) PyErr_Display(PyObject *, PyObject *, PyObject *);
DL_IMPORT(int) Py_AtExit(void (*func)(void));