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/epl_sample.txt

@@ -0,0 +1,11 @@
+
+N
+q812
+Q1218,26; q and Q values edited to reflect 4x6 inch size at 203 dpi
+B5,26,0,1A,3,7,152,B,"1234"
+A310,26,0,3,1,1,N,"SKU 00000 MFG 0000"
+A310,56,0,3,1,1,N,"QZ-Tray Java Application"
+A310,86,0,3,1,1,N,"TEST PRINT SUCCESSFUL"
+A310,116,0,3,1,1,N,"FROM SAMPLE.HTML"
+A310,146,0,3,1,1,N,"EDIT EPL_SAMPLE.TXT"
+P1,1