Merge branch '39-improve-game-architecture' into 'master'

lib/ui/layout/parameters.dart

lib/ui/layout/tileset.dart

lib/ui/painters/board_painter.dart

lib/ui/screens/about_page.dart

lib/ui/screens/game_page.dart

lib/ui/screens/settings_page.dart

lib/ui/skeleton.dart

lib/ui/widgets/app_bar.dart

lib/ui/widgets/bottom_nav_bar.dart

lib/ui/widgets/game/indicator_top.dart

lib/ui/widgets/game/message_game_end.dart

lib/ui/widgets/game/select_color_bar.dart

lib/ui/widgets/header_app.dart

lib/ui/widgets/home/button_game_restart.dart

lib/ui/widgets/home/button_game_start_new.dart

lib/ui/widgets/settings/settings_form.dart

lib/ui/widgets/settings/theme_card.dart

lib/utils/board_utils.dart

lib/utils/color_theme.dart

lib/utils/game_utils.dart