Add version gating for Zmq and Qt deprecations (#470)

* ZmqLogger: Avoid deprecated send() in later ZMQ
* QtImageReader: byteCount() deprecated in QT 5.10+

src/QtImageReader.cpp

@@ -111,7 +111,12 @@ void QtImageReader::Open()
 		info.has_audio = false;
 		info.has_video = true;
 		info.has_single_image = true;
-		info.file_size = image->byteCount();
+		#if QT_VERSION >= QT_VERSION_CHECK(5, 10, 0)
+			// byteCount() is deprecated from Qt 5.10
+			info.file_size = image->sizeInBytes();
+		#else
+			info.file_size = image->byteCount();
+		#endif
 		info.vcodec = "QImage";
 		info.width = image->width();
 		info.height = image->height();

src/ZmqLogger.cpp

@@ -120,14 +120,20 @@ void ZmqLogger::Log(string message)
 	// Create a scoped lock, allowing only a single thread to run the following code at one time
 	const GenericScopedLock<CriticalSection> lock(loggerCriticalSection);
 
+#if ZMQ_VERSION >= ZMQ_MAKE_VERSION(4, 3, 1)
 	// Send message over socket (ZeroMQ)
+	zmq::message_t reply(message);
+
+	// Set flags for immediate delivery (new API)
+	publisher->send(reply, zmq::send_flags::dontwait);
+#else
 	zmq::message_t reply (message.length());
 	memcpy (reply.data(), message.c_str(), message.length());
 	publisher->send(reply);
+#endif
 
-	// Write to log file (if opened, and force it to write to disk in case of a crash)
-	if (log_file.is_open())
-		log_file << message << std::flush;
+	// Also log to file, if open
+	LogToFile(message);
 }
 
 // Log message to a file (if path set)