Use built in sort indicator of ListView control (on windows), wx doesn't...

Use built in sort indicator of ListView control (on windows), wx doesn't provide this, so we do some Win32 programming.

src/gui/control/item_list.cpp

@@ -201,13 +201,27 @@ void ItemList::sortBy(long column, bool ascending) {
 }
 
 void ItemList::SetColumnImage(int col, int image) {
+	#if defined(__WXMSW__) && defined(HDF_SORTUP)
+		if ( wxApp::GetComCtl32Version() >= 470 ) {
+			// use built in sort indicator
+			HWND header = ListView_GetHeader(GetHwnd());
+			HDITEM header_item = {0};
+			header_item.mask = HDI_FORMAT;
+			Header_GetItem(header, col, &header_item);
+			header_item.fmt  &= ~(HDF_SORTUP | HDF_SORTDOWN);
+			if (image == 0) header_item.fmt |= HDF_SORTUP;
+			if (image == 1) header_item.fmt |= HDF_SORTDOWN;
+			Header_SetItem(header, col, &header_item);
+			return;
+		}
+	#endif
 	// The wx version of this function is broken,
 	// setting the wxLIST_MASK_IMAGE also sets the FORMAT flag, so we lose alignment info
 	wxListItem item;
 	item.SetMask(wxLIST_MASK_IMAGE | wxLIST_MASK_FORMAT);
 	GetColumn(col, item);
-    item.SetImage(image);
-    SetColumn(col, item);
+	item.SetImage(image);
+	SetColumn(col, item);
 }
 
 // ----------------------------------------------------------------------------- : ItemList : Window events