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/coreplugin/featureprovider.cpp

@@ -0,0 +1,111 @@
+/**************************************************************************
+**
+** This file is part of Qt Creator
+**
+** Copyright (c) 2011 Nokia Corporation and/or its subsidiary(-ies).
+**
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+**
+** GNU Lesser General Public License Usage
+**
+** This file may be used under the terms of the GNU Lesser General Public
+** License version 2.1 as published by the Free Software Foundation and
+** appearing in the file LICENSE.LGPL included in the packaging of this file.
+** Please review the following information to ensure the GNU Lesser General
+** Public License version 2.1 requirements will be met:
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights. These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** Other Usage
+**
+** Alternatively, this file may be used in accordance with the terms and
+** conditions contained in a signed written agreement between you and Nokia.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**************************************************************************/
+
+#include "featureprovider.h"
+
+/*!
+    \class Core::IFeatureProvider
+    \mainclass
+
+    \brief The class IFeatureProvider defines an interface to manage features for wizards
+
+    The features provided by an object in the object pool implementing IFeatureProvider
+    will be respected by wizards implementing IWizard.
+
+    This feature set, provided by all instances of IFeatureProvider in the object pool, is checked against IWizard::requiredFeatures()
+    and only if all required features are available the wizard is displayed when creating a new file or project.
+
+    Qt4VersionManager creates an instance of IFeatureProvider and provides Qt specific features for the available
+    versions of Qt.
+
+    \sa Core::IWizard
+    \sa QtSupport::QtVersionManager
+*/
+
+
+/*!
+    \fn IFeatureProvider::IFeatureProvider()
+    \internal
+*/
+
+/*!
+    \fn IFeatureProvider::~IFeatureProvider()
+    \internal
+*/
+
+/*!
+    \fn FeatureProvider::Features availableFeatures() const;
+    Returns available features provided by this manager.
+    \sa FeatureProvider::Features
+*/
+
+/*!
+    \class Core::FeatureProvider::Feature
+
+    \brief This class describes a single Feature
+
+    This class describes a single Feature to be used
+    in Core::FeatureProvider::Features.
+
+    \sa Core::FeatureProvider::Features
+    \sa Core::IWizard
+    \sa QtSupport::QtVersionManager
+*/
+
+/*!
+    \class Core::FeatureProvider::Features
+
+    \brief This class is a set of features
+
+    Features is used to describe available or
+    required feature sets and behaves similar to QFlags.
+
+    But instead of enums Features relies on string ids
+    and is therefore extendable.
+
+    \sa Core::FeatureProvider::Feature
+    \sa Core::IWizard
+    \sa QtSupport::QtVersionManager
+*/
+
+
+/*!
+    \fn bool Features::~contains(const Feature &feature)()
+
+    \returns true if the \param features is available.
+*/
+
+/*!
+    \fn bool Features::~contains(const Features &features)()
+
+    \returns true if all \param features are available.
+*/