Merge branch '41-improve-game-architecture' into 'master'

assets/skins/default_5.png

assets/skins/default_6.png

assets/skins/default_7.png

assets/skins/default_8.png

assets/translations/en.json

assets/translations/fr.json

fastlane/metadata/android/en-US/changelogs/39.txt

fastlane/metadata/android/fr-FR/changelogs/39.txt

icons/build_game_icons.sh

icons/colors_5.svg

icons/colors_6.svg

icons/colors_7.svg

icons/colors_8.svg

icons/level_easy.svg

icons/level_hard.svg

icons/level_medium.svg

icons/level_nightmare.svg

icons/size_extra.svg

icons/size_large.svg

icons/size_medium.svg