Add non focusable components. (#172)

include/ftxui/component/component_base.hpp

src/ftxui/component/button.cpp

src/ftxui/component/checkbox.cpp

src/ftxui/component/component.cpp

src/ftxui/component/container.cpp

src/ftxui/component/container_test.cpp

src/ftxui/component/input.cpp

src/ftxui/component/menu.cpp

src/ftxui/component/radiobox.cpp

src/ftxui/component/slider.cpp

src/ftxui/component/toggle.cpp