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.R

@@ -0,0 +1,38 @@
+#
+# Echoes the signed message and exits
+# usage:  R sign-message.R "test"
+#
+
+#########################################################
+#             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                                   #
+#                                                       #
+#########################################################
+
+library(openssl)
+
+mykey <- "private-key.pem"
+
+# Treat command line argument as message to be signed
+message <- enc2utf8(commandArgs(trailingOnly = TRUE))
+
+# Load the private key
+key <- read_key(file = mykey, password = mypass)
+
+# Create the signature
+sig <- signature_create(serialize(message, NULL), hash = sha512, key = key) # Use hash = sha1 for QZ Tray 2.0 and older
+
+print(sig)