Doc: replace Qt GUI Application with Qt Widgets Application

Qt GUI application could also be a Qt Quick application.
Update screenshots.

Task-number: QTCREATORBUG-10263

Change-Id: I8c0dd34e1222c3b42fddaf3f562e402490ce1037
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Reviewed-by: Eike Ziller <eike.ziller@digia.com>

doc/src/projects/creator-projects-creating.qdoc

@@ -98,7 +98,7 @@
 
         \list
 
-            \li Qt GUI Application
+            \li Qt Widgets Application
 
                 Use \QD forms to design a Qt widget based user interface for the
                 desktop and C++ to implement the application logic

doc/src/widgets/qtdesigner-app-tutorial.qdoc

@@ -42,7 +42,7 @@
 
     \list 1
 
-        \li Select \gui{File > New File or Project > Applications > Qt Gui
+        \li Select \gui{File > New File or Project > Applications > Qt Widgets
             Application > Choose}.
 
             \image qtcreator-new-qt-gui-application.png "New File or Project dialog"

src/plugins/qt4projectmanager/wizards/guiappwizard.cpp

@@ -78,7 +78,7 @@ GuiAppWizard::GuiAppWizard(bool isMobile)
     setCategory(QLatin1String(ProjectExplorer::Constants::QT_APPLICATION_WIZARD_CATEGORY));
     setDisplayCategory(QCoreApplication::translate("ProjectExplorer",
                ProjectExplorer::Constants::QT_APPLICATION_WIZARD_CATEGORY_DISPLAY));
-    setDisplayName(tr("Qt Gui Application"));
+    setDisplayName(tr("Qt Widgets Application"));
     setDescription(tr("Creates a Qt application for the desktop. "
                   "Includes a Qt Designer-based main window.\n\n"
                   "Preselects a desktop Qt for building the application if available."));

src/plugins/qt4projectmanager/wizards/guiappwizarddialog.cpp

@@ -57,7 +57,7 @@ GuiAppWizardDialog::GuiAppWizardDialog(const QString &templateName,
     setWindowTitle(templateName);
     setSelectedModules(QLatin1String("core gui"), true);
 
-    setIntroDescription(tr("This wizard generates a Qt GUI application "
+    setIntroDescription(tr("This wizard generates a Qt Widgets Application "
          "project. The application derives by default from QApplication "
          "and includes an empty widget."));