Use angle brackets (<>) rather than quotes ("") for the include
directives in our .h files. This should avoid some potentially nasty
surprises for Winelib apps.

include/d3dhal.h

diff --git a/include/d3dhal.h b/include/d3dhal.h
index b8908e4..2c0a439 100644
--- a/include/d3dhal.h
+++ b/include/d3dhal.h
@@ -26,7 +26,7 @@
 extern "C" {
 #endif
 
-#include "d3d.h"
+#include <d3d.h>
 
 /*****************************************************************************
  * device info structures