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/assets/signing/sign-message.node.js

@@ -0,0 +1,43 @@
+/*
+ * Node.js signing example
+ * Echoes the signed message and exits
+ */
+
+// #########################################################
+// #             WARNING   WARNING   WARNING               #
+// #########################################################
+// #                                                       #
+// # This file is intended for demonstration purposes      #
+// # only.                                                 #
+// #                                                       #
+// # It is the SOLE responsibility of YOU, the programmer  #
+// # to prevent against unauthorized access to any signing #
+// # functions.                                            #
+// #                                                       #
+// # Organizations that do not protect against un-         #
+// # authorized signing will be black-listed to prevent    #
+// # software piracy.                                      #
+// #                                                       #
+// # -QZ Industries, LLC                                   #
+// #                                                       #
+// #########################################################
+
+var key = "private-key.pem";
+//var pass = "S3cur3P@ssw0rd";
+
+app.get('/sign', function(req, res) {
+    var crypto = require('crypto');
+    var fs = require('fs');
+    var path = require('path');
+    var toSign = req.query.requestToSign;
+
+    fs.readFile(path.join(__dirname, '\\' + key), 'utf-8', function(err, privateKey) {
+        var sign = crypto.createSign('SHA512'); // Use "SHA1" for QZ Tray 2.0 and older
+
+        sign.update(toSign);
+        var signature = sign.sign({ key: privateKey/*, passphrase: pass */ }, 'base64');
+
+        res.set('Content-Type', 'text/plain');
+        res.send(signature);
+    });
+});