Retire Application class

It is a redundant boiler plate, just call initialization and
resource release directly from main()

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>

src/benchmark.cpp

@@ -102,7 +102,7 @@ void benchmark(int argc, char* argv[]) {
       if (!fenFile.is_open())
       {
           cerr << "Unable to open positions file " << posFile << endl;
-          Application::exit_with_failure();
+          exit(EXIT_FAILURE);
       }
       string pos;
       while (fenFile.good())