Added a member of a property bar to the main window.
Corrected tetengo2::gui::widget::map_box and side_bar.
Implemented bobura::message::main_window::window_resized.
Implemented bobura::message::main_window::window_resized.
Commented out the unused parameters.
Corrected #includes.
Modified the border style of custom controls.
Implemented tetengo2::gui::widget::side_bar.
Implemented tetengo2::detail::windows/stub::system_color.
Implemented tetengo2::gui::widget::side_bar.
Corrected tetengo2::detail::windows::message_handler.
Corrected Doxygen comment.