[welcome] Add QML support

- test application to display the QML (this will be extended
   with adding the locale model to it)
 - sample QML that does nothing useful yet (will display the locale
   model once it's there)

src/modules/welcome/CMakeLists.txt

@@ -40,3 +40,6 @@ calamares_add_plugin( welcome
         Qt5::Network
     SHARED_LIB
 )
+
+add_executable( welcomeqmltest qmlmain.cpp )
+target_link_libraries( welcomeqmltest calamaresui )

src/modules/welcome/qmlmain.cpp

@@ -0,0 +1,52 @@
+/* Example executable showing a QML page and using the
+ * models from libcalamares for displaying a welcome.
+ */
+
+#include <QApplication>
+#include <QLabel>
+#include <QMainWindow>
+#include <QQuickWidget>
+#include <QString>
+#include <QTimer>
+#include <QUrl>
+#include <QVBoxLayout>
+#include <QWidget>
+
+#include <KAboutData>
+
+#include "utils/Logger.h"
+
+int main(int argc, char **argv)
+{
+    QApplication a( argc, argv );
+
+    KAboutData aboutData( "calamares",
+                          "Calamares",
+                          "0.1",
+                          "Calamares QML Test Application",
+                          KAboutLicense::GPL_V3,
+                          QString(),
+                          QString(),
+                          "https://calamares.io",
+                          "https://github.com/calamares/calamares/issues" );
+    KAboutData::setApplicationData( aboutData );
+    a.setApplicationDisplayName( QString() );  // To avoid putting an extra "Calamares/" into the log-file
+
+    Logger::setupLogLevel( Logger::LOGVERBOSE );
+
+    QMainWindow mw;
+    QWidget background;
+    QVBoxLayout vl;
+    QLabel l( "Hello, world", &mw );
+    QQuickWidget qqw( &mw );
+    vl.addWidget( &qqw );
+    vl.addWidget( &l );
+    background.setLayout( &vl );
+    mw.setCentralWidget( &background );
+    mw.resize( QSize( 400, 400 ) );
+    mw.show();
+
+    qqw.setSource( QUrl::fromLocalFile("../src/modules/welcome/welcome.qml") );
+
+    return a.exec();
+}

src/modules/welcome/welcome.qml

@@ -0,0 +1,12 @@
+import QtQuick 2.0;
+
+Rectangle {
+    width: 200;
+    height: 200;
+    color: "pink";
+
+    Text {
+        anchors.centerIn: parent;
+        text: "Welcome to Calamares";
+    }
+}