IterationProxy for controlled access to embedded containers.
Switch access to SystemBody::m_children to IterationProxy interface.
Switch access to Space::m_bodies to IterationProxy interface.
Switch access to Frame::m_children to IterationProxy interface.
Switch access to UI::Container::m_widgets to IterationProxy interface.
Switch access to Lang::Resource::m_strings to IterationProxy interface.
Merge branch 'iteration_proxy'