Set the programname argument required in the test_util.h, to be the passed in test name in test.h.

Similar to:

    public:
    test(const std::string &config, const std::string &name)
    {
        progname = name.c_str();

Additionally change test_util.h to instead of using _func to using: PRETTY_FUNCTION_.

This will make the error messages output a lot more human readable.