[glibmm] (8 commits) Created branch refptr_as_sharedptr_v4

[Murray Cumming <murrayc src gnome org>]

The branch 'refptr_as_sharedptr_v4' was created.

Summary of new commits:

  ca6c036... Socket: Avoid creating a RefPtr to this.
  411772b... IOChannel: Avoid creating a RefPtr to this.
  ae7184d... Add and use make_refptr_for_instance().
  b3efb57... RefPtr: Make this an alias for shared_ptr<> instead.
  1fb7d37... glibmm_weakref: Don't try to use moved-from RefPtrs.
  34dd79f... glibmm_weakref: fix get()
  ed3cde0... Use std::dynamic_pointer_cast<>().
  a73842e... Remove Glib::WeakRef