Add custom QZ Tray fork with pairing key authentication

- Custom fork of QZ Tray 2.2.x with certificate validation bypassed
- Implemented pairing key (HMAC) authentication as replacement
- Modified files: PrintSocketClient.java (certificate check disabled)
- New files: PairingAuth.java, PairingConfigDialog.java
- Excluded build artifacts (out/, lib/javafx*) from repository
- Library JARs included for dependency management

tray/src/qz/communication/SocketIO.java

@@ -0,0 +1,100 @@
+package qz.communication;
+
+import org.apache.commons.lang3.ArrayUtils;
+import org.codehaus.jettison.json.JSONException;
+import org.codehaus.jettison.json.JSONObject;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import qz.utils.DeviceUtilities;
+import qz.utils.NetworkUtilities;
+import qz.ws.SocketConnection;
+
+import java.io.DataInputStream;
+import java.io.DataOutputStream;
+import java.io.IOException;
+import java.net.Socket;
+import java.nio.charset.Charset;
+import java.util.ArrayList;
+
+public class SocketIO implements DeviceListener {
+
+    private static final Logger log = LogManager.getLogger(SocketIO.class);
+
+    private String host;
+    private int port;
+    private Charset encoding;
+
+    private Socket socket;
+    private DataOutputStream dataOut;
+    private DataInputStream dataIn;
+
+    private SocketConnection websocket;
+
+    public SocketIO(String host, int port, Charset encoding, SocketConnection websocket) {
+        this.host = host;
+        this.port = port;
+        this.encoding = encoding;
+        this.websocket = websocket;
+    }
+
+    public boolean open() throws IOException {
+        socket = new Socket(host, port);
+        socket.setSoTimeout(NetworkUtilities.SOCKET_TIMEOUT);
+        dataOut = new DataOutputStream(socket.getOutputStream());
+        dataIn = new DataInputStream(socket.getInputStream());
+
+        return socket.isConnected();
+    }
+
+    public boolean isOpen() {
+        return socket.isConnected();
+    }
+
+    public void sendData(JSONObject params) throws JSONException, IOException {
+        log.debug("Sending data over [{}:{}]", host, port);
+        dataOut.write(DeviceUtilities.getDataBytes(params, encoding));
+        dataOut.flush();
+    }
+
+    public String processSocketResponse() throws IOException {
+        byte[] response = new byte[1024];
+        ArrayList<Byte> fullResponse = new ArrayList<>();
+        do {
+            int size = dataIn.read(response);
+            for(int i = 0; i < size; i++) {
+                fullResponse.add(response[i]);
+            }
+        }
+        while(dataIn.available() > 0);
+        if(fullResponse.size() > 0) {
+            return new String(ArrayUtils.toPrimitive(fullResponse.toArray(new Byte[0])), encoding);
+        }
+        return null;
+    }
+
+    @Override
+    public void close() {
+        // Remove orphaned reference
+        websocket.removeNetworkSocket(String.format("%s:%s", host, port));
+
+        try {
+            dataOut.close();
+        } catch(IOException e) {
+            log.warn("Could not close socket output stream", e);
+        }
+        try {
+            socket.close();
+        } catch(IOException e) {
+            log.warn("Could not close socket", e);
+        }
+    }
+
+    public String getHost() {
+        return host;
+    }
+
+    public int getPort() {
+        return port;
+    }
+
+}