Redo widgets
- box.cc

- Gtk_Container::Include, Customize (tooltips)
  (override default include call)

- isBasic (e.g. menu)

- check whether Widget hierarchy is correct

- needed widgets for construction

- solve the needed pointer stuff in a decent manner

- for container an add_child call (overloaded, bins should share it)

- AddChildren part of Customize or not?

- Adjustment stuff

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- typedef Foo Parent;