Mention that wxDV_ROW_LINES is not implemented in the generic version.

wxDV_ROW_LINES is currently only supported by the native implementations of
wxDataViewCtrl.

See #12834.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@66563 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

interface/wx/dataview.h

@@ -667,6 +667,8 @@ public:
            Multiple selection mode.
     @style{wxDV_ROW_LINES}
            Use alternating colours for rows if supported by platform and theme.
+           Currently only supported by the native GTK and OS X implementations
+           but not by the generic one.
     @style{wxDV_HORIZ_RULES}
            Display fine rules between row if supported.
     @style{wxDV_VERT_RULES}