Added trivial test executable which doesn't use Catch's main() function.

projects/SelfTest/TestExternalMain.cpp

@@ -0,0 +1,14 @@
+/*
+ *  Created by Fraser on 07/03/2014.
+ *  Copyright 2014 Two Blue Cubes Ltd
+ *
+ *  Distributed under the Boost Software License, Version 1.0. (See accompanying
+ *  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+ */
+
+#define CATCH_CONFIG_RUNNER
+#include "catch.hpp"
+
+int main (int argc, char * const argv[]) {
+    return Catch::Session().run( argc, argv );
+}