Only use std::cout/ cert via Catch::cout/ cert - and make those conditional on CATCH_CONFIG_NOSTDOUT

include/internal/catch_runner_impl.hpp

@@ -262,8 +262,8 @@ namespace Catch {
                 Timer timer;
                 timer.start();
                 if( m_reporter->getPreferences().shouldRedirectStdOut ) {
-                    StreamRedirect coutRedir( std::cout, redirectedCout );
-                    StreamRedirect cerrRedir( std::cerr, redirectedCerr );
+                    StreamRedirect coutRedir( Catch::cout(), redirectedCout );
+                    StreamRedirect cerrRedir( Catch::cerr(), redirectedCerr );
                     invokeActiveTestCase();
                 }
                 else {