0022972: Eliminate macro definitions that has compiler-provided analogs (WNT and so on)

1) Macro definition WNT replaced by _WIN32 and _MSC_VER for platform and compiler detection accordingly.
2) Macro definition LIN replaced by __linux__ macro.
3) Macro definition DEB replaced by OCCT_DEBUG macro.

src/Aspect/Aspect_Drawable.hxx

@@ -22,10 +22,10 @@
 #ifndef _Aspect_Drawable_HeaderFile
 #define _Aspect_Drawable_HeaderFile
 
-#ifdef WNT
+#ifdef _WIN32
  typedef void*        Aspect_Drawable;	/* HDC under WNT */
 #else
  typedef unsigned long Aspect_Drawable;	/* Window or Pixmap under UNIX */
-#endif /* WNT */
+#endif /* _WIN32 */
 
 #endif /* _Aspect_Drawable_HeaderFile */

src/Aspect/Aspect_Handle.hxx

@@ -21,11 +21,11 @@
 #ifndef _Aspect_Handle_HeaderFile
 #define _Aspect_Handle_HeaderFile
 
-#ifdef WNT
+#ifdef _WIN32
  typedef void*         HANDLE;
  typedef HANDLE        Aspect_Handle;
 #else
  typedef unsigned long Aspect_Handle;
-#endif /* WNT */
+#endif /* _WIN32 */
 
 #endif /* _Aspect_Handle_HeaderFile */

src/Aspect/Aspect_XWD.hxx

@@ -89,5 +89,5 @@ typedef struct _xcolor {
 
                } XColor;
 
-# endif /* WNT */
+# endif /* _WIN32 */
 #endif  /* __Aspect_WNTXWD_HXX */