Move IVoice enum registration into static method

refs #183

src/blackcore/blackcorefreefunctions.h

@@ -0,0 +1,21 @@
+/*  Copyright (C) 2013 VATSIM Community / contributors
+ *  This Source Code Form is subject to the terms of the Mozilla Public
+ *  License, v. 2.0. If a copy of the MPL was not distributed with this
+ *  file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef BLACKCORE_FREEFUNCTIONS_H
+#define BLACKCORE_FREEFUNCTIONS_H
+
+/*!
+ * Free functions in BlackSim
+ */
+namespace BlackCore
+{
+    /*!
+     * \brief Register all relevant metadata in BlackCore
+     */
+    void registerMetadata();
+
+} // BlackCore
+
+#endif // guard