Changes are now persisted when application is closed while the Snackbar is opened.

Edit list menu button is now outside the menu, with an icon
New menu button to allow faster layout changing (does the same as going in the Settings)
Current opened tab is now saved when re-opening app

DoNExt/app/src/main/res/values/strings.xml

@@ -6,6 +6,7 @@
     <string name="action_editTabs">Edit lists</string>
     <string name="action_about">About</string>
     <string name="action_new_task">New task</string>
+    <string name="action_changeLayout">Change layout</string>
     <string name="settings_activity_title">Settings</string>
 
     <!-- Strings related to Task List edition -->