Merge branch 'listctrl-extend-rules-and-zebra'

Allow extending rules and zebra background in wxListCtrl to the whole
window.

See https://github.com/wxWidgets/wxWidgets/pull/2112

interface/wx/listctrl.h

@@ -1333,6 +1333,33 @@ public:
     */
     void CheckItem(long item, bool check);
 
+    /**
+        Extend rules and alternate rows background to the entire client area.
+
+        Bu default, the rules (when enabled with wxLC_HRULES and wxLC_VRULES)
+        and alternate row background (when EnableAlternateRowColours() was
+        called) are only shown in the part of the control occupied by the
+        items, which can be smaller than the entire window if there are few
+        items in the control.
+
+        Calling this function extends the display of the rules and alternate
+        background rows to the entire client area.
+
+        Similarly to EnableAlternateRowColours(), this method can only be used
+        with controls having ::wxLC_REPORT and ::wxLC_VIRTUAL styles.
+
+        Note that this method is currently not implemented in the native MSW
+        version and does nothing there.
+
+        @param extend
+            if @true, draws horizontal rules and vertical rules on empty rows
+            and uses the colour parameter to paint the background of
+            alternate rows when those rows are blank, empty, with no data.
+
+        @since 3.1.5
+    */
+    void ExtendRulesAndAlternateColour(bool extend = true);
+
 protected:
 
     /**