Document the rule that Python.h must be included before any standard

headers.  This is the final checkin for SF bug #458768.

Doc/api/api.tex

@@ -76,6 +76,9 @@ API are included in your code by the following line:
 This implies inclusion of the following standard headers:
 \code{<stdio.h>}, \code{<string.h>}, \code{<errno.h>},
 \code{<limits.h>}, and \code{<stdlib.h>} (if available).
+Since Python may define some pre-processor definitions which affect
+the standard headers on some systems, you must include \file{Python.h}
+before any standard headers are included.
 
 All user visible names defined by Python.h (except those defined by
 the included standard headers) have one of the prefixes \samp{Py} or

Doc/ext/extending.tex

@@ -46,8 +46,11 @@ The first line of our file can be:
 
 which pulls in the Python API (you can add a comment describing the
 purpose of the module and a copyright notice if you like).
+Since Python may define some pre-processor definitions which affect
+the standard headers on some systems, you must include \file{Python.h}
+before any standard headers are included.
 
-All user-visible symbols defined by \code{"Python.h"} have a prefix of
+All user-visible symbols defined by \file{Python.h} have a prefix of
 \samp{Py} or \samp{PY}, except those defined in standard header files.
 For convenience, and since they are used extensively by the Python
 interpreter, \code{"Python.h"} includes a few standard header files:
@@ -951,7 +954,6 @@ Geoff Philbrick (\email{philbrick@hks.com}):%
 \index{Philbrick, Geoff}
 
 \begin{verbatim}
-#include <stdio.h>
 #include "Python.h"
 
 static PyObject *