Negative infinity round-trips as invalid JSON

Describe the bug
inf and -inf don't round trip if useSpecialFloats is false.

To Reproduce
Steps to reproduce the behavior:

	Json::Value testJson(Json::arrayValue);
	testJson[0] = 25.0;
	testJson[1] = 0.0;
	testJson[2] = -std::numeric_limits<float>::infinity();
	Json::StreamWriterBuilder builder;
	builder["indentation"] = "\t";
        // both false/true are incorrect
	//builder["useSpecialFloats"] = true;
	const std::unique_ptr<Json::StreamWriter> writer(builder.newStreamWriter());
	std::stringstream ss;
	writer->write(testJson, &ss);
	Json::Reader reader;
	Json::Value json;

	bool is_valid = reader.parse(ss, json);
	// is_valid == false
        // errors list -1e+9999 as invalid number

Expected behavior
Should at least parse rather than hard fail.

Desktop (please complete the following information):

• OS: Windows
• Ninja version 1.10.2

Start by running the supplied reproduction and inspect the Json::StreamWriterBuilder, Json::StreamWriter, and Json::Reader paths involved in serializing and parsing -inf. Done means the emitted value can be parsed without an invalid-number error while preserving the intended round trip.