Add more evidential comments, adjust code to follow coding style

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@77779 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/univ/textctrl.cpp

@@ -941,8 +941,10 @@ void wxTextCtrl::Replace(wxTextPos from, wxTextPos to, const wxString& text)
 {
     wxTextCoord colStart, colEnd,
                 lineStart, lineEnd;
-    // as convention, if `to` equal -1, it means go to the last position
-    if ( to == -1)
+    // as convention, ( src/gtk/textctrl.cpp:1411, src/msw/textctrl.cpp:759, 
+    // test/controls/textentrytest.cpp:171 )
+    // if `to` equal -1, it means go to the last position
+    if ( to == -1 )
         to = GetLastPosition();
 
     if ( (from > to) ||