add bigger margins around column title when autosizing column width based on it, it looks better like this

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@57258 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/headerctrlcmn.cpp

@@ -80,7 +80,7 @@ void wxHeaderCtrlBase::OnSeparatorDClick(wxHeaderCtrlEvent& event)
     const unsigned col = event.GetColumn();
 
     int w = wxWindowBase::GetTextExtent(GetColumn(col).GetTitle()).x;
-    w += 2*GetCharWidth(); // add some arbitrary margins around text
+    w += 4*GetCharWidth(); // add some arbitrary margins around text
 
     if ( !UpdateColumnWidthToFit(col, w) )
         event.Skip();