Wizards: allows filtering of wizards based on Qt version

Every wizard now implements requiredFeatures() to define a feature set.
If the feature set is not satisfied by the available Qt Versions,
the wizard is not shown in the create file/project dialog.

Every Qt version can define the provided feature set in availableFeatures()
defined in BaseQtVersion.

Change-Id: Ie9e2c210d19187b2296451948c36d274f2096623
Reviewed-by: Daniel Teske <daniel.teske@nokia.com>
Reviewed-by: Alessandro Portale <alessandro.portale@nokia.com>

src/plugins/designer/cpp/formclasswizard.cpp

@@ -35,6 +35,7 @@
 #include "designerconstants.h"
 #include "formwindoweditor.h"
 #include "qtdesignerformclasscodegenerator.h"
+#include <qtsupport/qtsupportconstants.h>
 
 #include <coreplugin/icore.h>
 #include <cppeditor/cppeditorconstants.h>
@@ -65,6 +66,11 @@ QString FormClassWizard::formSuffix() const
     return preferredSuffix(QLatin1String(Constants::FORM_MIMETYPE));
 }
 
+Core::FeatureSet FormClassWizard::requiredFeatures() const
+{
+    return Core::Feature(QtSupport::Constants::FEATURE_QWIDGETS);
+}
+
 QWizard *FormClassWizard::createWizardDialog(QWidget *parent,
                                              const QString &defaultPath,
                                              const WizardPageList &extensionPages) const