[gtkmm] C++11: TreeView: Use std::stod() instead of std::strtod().

[Murray Cumming <murrayc src gnome org>]

commit fcc0f358d17264f8956567a33471a6b52c2fc0d1
Author: Murray Cumming <murrayc murrayc com>
Date:   Tue Sep 1 12:51:21 2015 +0200

    C++11: TreeView: Use std::stod() instead of std::strtod().
    
    This also removes a using std::strtod() that really should not be in a header.

 gtk/src/treeview.hg |    7 +------
 1 files changed, 1 insertions(+), 6 deletions(-)
---
diff --git a/gtk/src/treeview.hg b/gtk/src/treeview.hg
index d6fad5a..1c671f5 100644
--- a/gtk/src/treeview.hg
+++ b/gtk/src/treeview.hg
@@ -34,10 +34,6 @@ _CONFIGINCLUDE(gtkmmconfig.h)
 _DEFS(gtkmm,gtk)
 _PINCLUDE(gtkmm/private/container_p.h)
 
-#include <cstdlib>
-
-using std::strtod;
-
 namespace Gtk
 {
 
@@ -1183,8 +1179,7 @@ void _auto_store_on_cellrenderer_text_edited_numerical(const Glib::ustring& path
       //new_value << astream; //Get it out of the stream as the numerical type.
 
       //Convert the text to a number, using the same logic used by GtkCellRendererText when it stores 
numbers.
-      char* pchEnd = nullptr;
-      ColumnType new_value = static_cast<ColumnType>( strtod(new_text.c_str(), &pchEnd) );
+      auto new_value = static_cast<ColumnType>( std::stod(new_text) );
 
       //Store the user's new text in the model:
       Gtk::TreeRow row = *iter;