added the ability to set custom app icons for windows / macos

simply add a line in sketch.properties
icon.windows=  or
icon.macos=
folow the = with the relative path to the icon file that you wish to use

java/src/processing/mode/java/JavaBuild.java

@@ -735,7 +735,18 @@ protected boolean exportApplication(File destFolder,
       File resourcesFolder = new File(contentsFolder, "Resources");
       Util.copyDir(new File(contentsOrig, "Resources/en.lproj"),
                    new File(resourcesFolder, "en.lproj"));
-      Util.copyFile(mode.getContentFile("application/application.icns"),
+
+      Settings sketchProperties = new Settings(new File(sketch.getFolder(), "sketch.properties"));
+      String iconPath = sketchProperties.get("icon");//icon.macos
+      File iconFile;
+      if(iconPath == null || iconPath.isEmpty()){
+        iconFile = mode.getContentFile("application/application.icns");
+        System.out.println("using default icon");
+      }else {
+        iconFile = new File(sketch.getFolder(), iconPath);
+        System.out.println("found custom icon: "+iconPath);
+      }
+      Util.copyFile(iconFile,
                     new File(resourcesFolder, "application.icns"));
 
     } else if (exportPlatform == PConstants.LINUX) {
@@ -958,7 +969,17 @@ protected boolean exportApplication(File destFolder,
       File exeFile = new File(destFolder, sketch.getName() + ".exe");
       config.addChild("outfile").setContent(exeFile.getAbsolutePath());
 
-      File iconFile = mode.getContentFile("application/application.ico");
+      //check sketch.properties to see if an icon was set
+      Settings sketchProperties = new Settings(new File(sketch.getFolder(), "sketch.properties"));
+      String iconPath = sketchProperties.get("icon");//icon.windows
+      File iconFile;
+      if(iconPath == null || iconPath.isEmpty()){
+        iconFile = mode.getContentFile("application/application.ico");
+        System.out.println("using default icon");
+      }else {
+        iconFile = new File(sketch.getFolder(), iconPath);
+        System.out.println("found custom icon: "+iconPath);
+      }
       config.addChild("icon").setContent(iconFile.getAbsolutePath());
 
       XML clazzPath = config.addChild("classPath");