added const overload of GetChildren()

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@44414 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/latex/wx/sizer.tex

@@ -241,6 +241,8 @@ windows which manage it.
 
 \membersection{wxSizer::GetChildren}\label{wxsizergetchildren}
 
+\constfunc{const wxSizerItemList\&}{GetChildren}{\void}
+
 \func{wxSizerItemList\&}{GetChildren}{\void}
 
 Returns the list of the items in this sizer. The elements of type-safe 

include/wx/sizer.h

@@ -550,6 +550,8 @@ public:
 
     wxSizerItemList& GetChildren()
         { return m_children; }
+    const wxSizerItemList& GetChildren() const
+        { return m_children; }
 
     void SetDimension( int x, int y, int width, int height );