Merge branch '21-clean-improve-update-code' into 'master'

Resolve "Clean / improve / update code"

Closes #21

See merge request !20

assets/translations/en.json

+{
+  "app_name": "Reversi",
+
+  "settings_title": "Settings",
+  "settings_label_theme": "Theme mode",
+
+  "about_title": "Informations",
+  "about_content": "Reversi",
+  "about_version": "Version: {version}",
+
+  "": ""
+}

assets/translations/fr.json

+{
+  "app_name": "Reversi",
+
+  "settings_title": "Réglages",
+  "settings_label_theme": "Thème de couleurs",
+
+  "about_title": "Informations",
+  "about_content": "Reversi.",
+  "about_version": "Version : {version}",
+
+  "": ""
+}

fastlane/metadata/android/en-US/changelogs/20.txt

+Clean / improve / update code and UI..

fastlane/metadata/android/fr-FR/changelogs/20.txt

+Nettoyage / amélioration / mise à jour de code et de l'interface.

icons/button_back.svg

+<?xml version="1.0" encoding="UTF-8"?>
+<svg enable-background="new 0 0 100 100" version="1.1" viewBox="0 0 93.665 93.676" xml:space="preserve" xmlns="http://www.w3.org/2000/svg"><path transform="matrix(1.3783 .61747 -.61747 1.3783 45.198 93.762)" d="m11.645-14.603-44.77-4.6003 26.369-36.472z" fill="#fff" stroke="#950e4f" stroke-linecap="round" stroke-linejoin="round" stroke-width="7.2832"/></svg>

icons/button_delete_saved_game.svg

+<?xml version="1.0" encoding="UTF-8"?>
+<svg enable-background="new 0 0 100 100" version="1.1" viewBox="0 0 93.665 93.676" xml:space="preserve" xmlns="http://www.w3.org/2000/svg"><path d="m76.652 23.303-3.6441 58.302c-0.28153 4.5103-4.0223 8.0241-8.5413 8.0241h-35.27c-4.5189 0-8.2598-3.5138-8.5413-8.0241l-3.6441-58.302h-5.4824c-1.7723 0-3.2093-1.437-3.2093-3.2093 0-1.773 1.437-3.2093 3.2093-3.2093h70.605c1.7723 0 3.2093 1.4363 3.2093 3.2093 0 1.7723-1.437 3.2093-3.2093 3.2093zm-6.8314 0h-45.979l3.0819 55.867c0.12535 2.268 2.0008 4.0433 4.2732 4.0433h31.268c2.2724 0 4.1478-1.7752 4.2732-4.0433zm-22.99 6.4188c1.6541 0 2.9952 1.3411 2.9952 2.9952v41.08c0 1.6541-1.3411 2.9952-2.9952 2.9952-1.6542 0-2.9952-1.3411-2.9952-2.9952v-41.08c0-1.6541 1.3411-2.9952 2.9952-2.9952zm-12.837 0c1.6756 0 3.0553 1.3181 3.1312 2.9921l1.8776 41.3c0.06665 1.4664-1.0681 2.7087-2.5345 2.7762-0.04011 0.0015-0.08024 0.0021-0.12108 0.0021-1.5595 0-2.8476-1.2193-2.9328-2.7774l-2.253-41.3c-0.08524-1.5646 1.114-2.9012 2.6779-2.9864 0.05157-0.0029 0.10317-0.0042 0.15474-0.0042zm25.675 0c1.5667 0 2.8361 1.2694 2.8361 2.8361 0 0.05156-6.87e-4 0.10317-0.0036 0.15474l-2.2416 41.088c-0.09171 1.6778-1.4786 2.991-3.1586 2.991-1.5667 0-2.8361-1.2694-2.8361-2.8361 0-0.05156 7.31e-4 -0.10315 0.0036-0.15474l2.2417-41.088c0.09172-1.6778 1.4786-2.991 3.1586-2.991zm-21.397-25.675h17.117c4.7265 0 8.5578 3.8313 8.5578 8.5578v4.2795h-34.231v-4.2795c0-4.7265 3.8313-8.5578 8.5578-8.5578zm0.42837 6.4188c-1.4184 0-2.5675 1.1491-2.5675 2.5675v3.8512h21.394v-3.8512c0-1.4184-1.1491-2.5675-2.5675-2.5675z" fill="#fff" fill-rule="evenodd" stroke="#050200"/></svg>