catch all exceptions in all tutorials and examples

examples/compute_tof.cpp

@@ -92,6 +92,7 @@ namespace
 // ----------------- Main program -----------------
 int
 main(int argc, char** argv)
+try
 {
     using namespace Opm;
 
@@ -297,3 +298,7 @@ main(int argc, char** argv)
               << "\n  Pressure time:  " << ptime
               << "\n  Transport time: " << ttime << std::endl;
 }
+catch (const std::exception &e) {
+    std::cerr << "Program threw an exception: " << e.what() << "\n";
+    throw;
+}