Freestyle: Fix for VC++ warnings about 'hypot' macro redefinitions (Part 2).

(See commit e1771e72fbbf828dbf5bed871b814288389f3611 for more detail of
the problem).

Fixed for #include <Python.h> not properly put in the extern "C" { ... } construct.

Also removed redundant inclusion of the header file in the Freestyle Python API code.

source/blender/freestyle/intern/python/Interface1D/BPy_Stroke.h

@@ -26,6 +26,7 @@
 #define __FREESTYLE_PYTHON_STROKE_H__
 
 #include "../BPy_Interface1D.h"
+
 #include "../../stroke/Stroke.h"
 
 #ifdef __cplusplus
@@ -34,8 +35,6 @@ extern "C" {
 
 ///////////////////////////////////////////////////////////////////////////////////////////
 
-#include <Python.h>
-
 extern PyTypeObject Stroke_Type;
 
 #define BPy_Stroke_Check(v)	(((PyObject *)v)->ob_type == &Stroke_Type)