[libcalamaresui] Register in io.calamares namespace

- Register both Branding and ViewManager for QML
- Note that this changes the name of Branding
- Add code-docs about object ownership

src/libcalamaresui/viewpages/QmlViewStep.cpp

@@ -74,10 +74,17 @@ registerCalamaresModels()
     if ( !done )
     {
         done = true;
+        // Because branding and viewmanager have a parent (CalamaresApplication
+        // and CalamaresWindow), they will not be deleted by QmlEngine.
+        //   https://doc.qt.io/qt-5/qtqml-cppintegration-data.html#data-ownership
         qmlRegisterSingletonType< Calamares::Branding >(
-            "calamares.ui", 1, 0, "Branding", []( QQmlEngine*, QJSEngine* ) -> QObject* {
+            "io.calamares.ui", 1, 0, "Branding", []( QQmlEngine*, QJSEngine* ) -> QObject* {
                 return Calamares::Branding::instance();
             } );
+        qmlRegisterSingletonType< Calamares::Branding >(
+            "io.calamares.core", 1, 0, "ViewManager", []( QQmlEngine*, QJSEngine* ) -> QObject* {
+                return Calamares::ViewManager::instance();
+            } );
     }
 }
 

src/modules/welcomeq/WelcomeQmlViewStep.cpp

@@ -52,7 +52,6 @@ WelcomeQmlViewStep::WelcomeQmlViewStep( QObject* parent )
 // 			 &WelcomeQmlViewStep::nextStatusChanged );
 //     emit nextStatusChanged(true);
     qmlRegisterSingletonType< Config >( "io.calamares.module", 1, 0, "Welcome", [&](QQmlEngine*, QJSEngine*) -> QObject* { return m_config; } );
-    qmlRegisterSingletonType< Calamares::Branding >( "io.calamares.ui", 1, 0, "Branding", [](QQmlEngine*, QJSEngine*) -> QObject* { return Calamares::Branding::instance(); } );
 }