First cut of new AssertionHandler/ Decomposer

- integrated into INTERNAL_CATCH_TEST. Needs more work to fully replace existing stuff

include/internal/catch_decomposer.cpp

@@ -0,0 +1,23 @@
+/*
+ *  Created by Phil Nash on 8/8/2017.
+ *  Copyright 2017 Two Blue Cubes Ltd. All rights reserved.
+ *
+ *  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)
+ */
+
+#include "catch_decomposer.h"
+#include "catch_config.hpp"
+
+namespace Catch {
+
+    void formatReconstructedExpression( std::ostream &os, std::string const& lhs, std::string const& op, std::string const& rhs ) {
+
+        if( lhs.size() + rhs.size() < 40 &&
+                lhs.find('\n') == std::string::npos &&
+                rhs.find('\n') == std::string::npos )
+            os << lhs << " " << op << " " << rhs;
+        else
+            os << lhs << "\n" << op << "\n" << rhs;
+    }
+}