refs #445, value objects and containers

* common base class for DB based classes
* common base class for DB based containers
* Livery, distributor value class
* adjusted value classes to livery
* utility functions for DB values (blackmisc free functions)
* register new objects with metadata system

src/blackmisc/datastoreutility.h

@@ -0,0 +1,40 @@
+/* Copyright (C) 2015
+ * swift project Community / Contributors
+ *
+ * This file is part of swift project. It is subject to the license terms in the LICENSE file found in the top-level
+ * directory of this distribution and at http://www.swift-project.org/license.html. No part of swift project,
+ * including this file, may be copied, modified, propagated, or distributed except according to the terms
+ * contained in the LICENSE file.
+ */
+
+//! \file
+
+#ifndef BLACKMISC_DATASTOREUTILITY_H
+#define BLACKMISC_DATASTOREUTILITY_H
+
+#include "blackmiscexport.h"
+#include "timestampbased.h"
+#include "propertyindex.h"
+#include "variant.h"
+
+namespace BlackMisc
+{
+    /*!
+     * Class with datastore related utilities
+     */
+    class CDatastoreUtility
+    {
+    public:
+        //! No constructor
+        CDatastoreUtility() = delete;
+
+        //! DB Bool value to bool
+        static bool dbBoolStringToBool(const QString &dbBool);
+
+        //! Extract key from string like "MyAircraft (33)"
+        static int extractIntegerKey(const QString &stringWithKey);
+    };
+
+} // namespace
+
+#endif // guard