Parsing the unparsed program_options options

static void add_unrecognized_options(TestConfiguration& config, const std::vector<string>& unrecognized_options)
{
	// TODO: make sure all unrecognized options are of the form --option=value

	// I'm sure the following can be made more elegant...

	enum { OptionName, OptionValue } now_expecting = OptionName;
	std::string option_name;
	for(auto it = unrecognized_options.begin(); it != unrecognized_options.end(); it++) {
		std::string option_value;
		if (now_expecting == OptionValue) {
			option_value = *it;
			// Note! Not checking for '=' or ' ' characters in option values, if we know it's a value
			if (option_value.find_first_not_of('-') == 2) {
				// Got another option instead of a value, must be a flag option
				// std::cout << "Inserting " << option_name << " as empty" << std::endl;
				config.extra_options.insert(make_pair(option_name, std::string()));
				option_name = option_value;
				now_expecting = OptionValue;
				continue;
			}
		}
		else {
			std::string s(*it);
			auto key_starts = s.find_first_not_of('-');
			util::enforce(key_starts != string::npos, "Couldn't determine option name for " + s);
			auto option_name_ends = s.find_first_of(" =\n", key_starts);
			if (option_name_ends == string::npos) {
				now_expecting = OptionValue;
				option_name = s.substr(key_starts);
				continue;
			}
			option_name = s.substr(key_starts, option_name_ends - key_starts);
			auto value_starts = s.find_first_not_of(" =\n", option_name_ends + 1);
			if (value_starts == string::npos) {
				now_expecting = OptionValue;
				continue;
			}
			// string value = s.substr(value_starts);
			option_value = s.substr(value_starts);
		}
		config.extra_options.insert(make_pair(option_name, option_value));
		now_expecting = OptionName;
	}
	if (now_expecting != OptionName) {
		config.extra_options.insert(make_pair(option_name, std::string()));
	}
}