should set window icon for windows.

desktop/build-osx.json

@@ -4,8 +4,8 @@
     "executable": "Tick's Tales", 
     "appjar": "target/advent-standalone.jar",
     "mainclass": "advent/core/desktop_launcher",
-    "resources": [
-    ],
+    "resources": ["resources/icon" ],
+    "vmargs": ["-Xdock:icon=icon/icon_128x128.png"],
     "minimizejre": "soft",
     "outdir": "target/osx/Tick's Tales.app"
 }