Allow choosing the widget variant in the widgets sample.

Add a menu for selecting wxWindowVariant to use for the widget.

samples/widgets/widgets.h

@@ -99,6 +99,7 @@ struct WidgetAttributes
 #endif // wxUSE_TOOLTIPS
         m_enabled = true;
         m_dir = wxLayout_LeftToRight;
+        m_variant = wxWINDOW_VARIANT_NORMAL;
         m_cursor = *wxSTANDARD_CURSOR;
         m_defaultFlags = wxBORDER_DEFAULT;
     }
@@ -114,6 +115,7 @@ struct WidgetAttributes
     wxColour m_colPageBg;
     bool m_enabled;
     wxLayoutDirection m_dir;
+    wxWindowVariant m_variant;
     wxCursor m_cursor;
     // the default flags, currently only contains border flags
     int m_defaultFlags;