[gtkmm-documentation] Adapt to Container::forall_vfunc() without include_internals parameter.

[Murray Cumming <murrayc src gnome org>]

commit 3f3b5e70b0547610e34c501037c1f238fddef333
Author: Murray Cumming <murrayc murrayc com>
Date:   Wed May 3 09:57:43 2017 +0200

    Adapt to Container::forall_vfunc() without include_internals parameter.

 .../book/custom/custom_container/mycontainer.cc    |    2 +-
 .../book/custom/custom_container/mycontainer.h     |    2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/examples/book/custom/custom_container/mycontainer.cc 
b/examples/book/custom/custom_container/mycontainer.cc
index bd52e15..0b8f6d9 100644
--- a/examples/book/custom/custom_container/mycontainer.cc
+++ b/examples/book/custom/custom_container/mycontainer.cc
@@ -181,7 +181,7 @@ void MyContainer::on_size_allocate(Gtk::Allocation& allocation)
     m_child_two->size_allocate(child_allocation_two);
 }
 
-void MyContainer::forall_vfunc(bool /* include_internals */, const ForeachSlot& slot)
+void MyContainer::forall_vfunc(const ForeachSlot& slot)
 {
   if (m_child_one)
     slot(*m_child_one);
diff --git a/examples/book/custom/custom_container/mycontainer.h 
b/examples/book/custom/custom_container/mycontainer.h
index 254ec17..1bb6c79 100644
--- a/examples/book/custom/custom_container/mycontainer.h
+++ b/examples/book/custom/custom_container/mycontainer.h
@@ -35,7 +35,7 @@ protected:
     int& minimum_baseline, int& natural_baseline) const override;
   void on_size_allocate(Gtk::Allocation& allocation) override;
 
-  void forall_vfunc(bool include_internals, const ForeachSlot& slot) override;
+  void forall_vfunc(const ForeachSlot& slot) override;
 
   void on_add(Gtk::Widget* child) override;
   void on_remove(Gtk::Widget* child) override;