Added include guards and C++ extern "C" {} constructs. Partial fix for #607253.
Bugfix candidate.
diff --git a/Include/pymactoolbox.h b/Include/pymactoolbox.h
index 5e2bb34..16f7352 100644
--- a/Include/pymactoolbox.h
+++ b/Include/pymactoolbox.h
@@ -1,7 +1,8 @@
 /*
 ** pymactoolbox.h - globals defined in mactoolboxglue.c
 */
-
+#ifndef Py_PYMACTOOLBOX_H
+#define Py_PYMACTOOLBOX_H
 #ifdef __cplusplus
 	extern "C" {
 #endif
@@ -197,3 +198,4 @@
 #ifdef __cplusplus
 	}
 #endif
+#endif