[test.common_timedlogging] added first draft

dune/stuff/test/common_timedlogging.cc

+// This file is part of the dune-stuff project:
+//   https://github.com/wwu-numerik/dune-stuff
+// Copyright holders: Rene Milk, Felix Schindler
+// License: BSD 2-Clause License (http://opensource.org/licenses/BSD-2-Clause)
+
+#include "main.hxx"
+
+#include <dune/stuff/common/logging.hh>
+
+using namespace Dune;
+using namespace Dune::Stuff;
+using namespace Dune::Stuff::Common;
+
+
+TEST(TimedPrefixedLogStream, all)
+{
+  Timer timer;
+  TimedPrefixedLogStream out(timer, "prefix", std::cout);
+  out << "there should follow a blank line\n\nand some text, followed by std::flush" << std::flush;
+  out << "\n\nthis line should be preceded by a blank line and followed by std::endl" << std::endl;
+}