Properly shutdown everything on window close

- Properly shutdown applet on window close
- Properly remove system tray icon on close
- Shutdown executorService on shutdown

Signed-off-by: Tomas Slusny <slusnucky@gmail.com>

runelite-client/src/main/java/net/runelite/client/RuneLite.java

@@ -35,6 +35,7 @@ import java.io.File;
 import java.lang.management.ManagementFactory;
 import java.lang.management.RuntimeMXBean;
 import java.util.Locale;
+import java.util.concurrent.ScheduledExecutorService;
 import javax.annotation.Nullable;
 import javax.inject.Provider;
 import javax.inject.Singleton;
@@ -111,6 +112,9 @@ public class RuneLite
 	@Inject
 	private OverlayManager overlayManager;
 
+	@Inject
+	private ScheduledExecutorService executorService;
+
 	@Inject
 	private Provider<ItemManager> itemManager;
 
@@ -294,6 +298,7 @@ public class RuneLite
 	{
 		clientSessionManager.shutdown();
 		discordService.close();
+		executorService.shutdown();
 	}
 
 	@VisibleForTesting

runelite-client/src/main/java/net/runelite/client/ui/ClientUI.java

@@ -36,6 +36,7 @@ import java.awt.Graphics;
 import java.awt.GraphicsConfiguration;
 import java.awt.LayoutManager;
 import java.awt.Rectangle;
+import java.awt.SystemTray;
 import java.awt.TrayIcon;
 import java.awt.image.BufferedImage;
 import javax.annotation.Nullable;
@@ -267,6 +268,21 @@ public class ClientUI
 				{
 					saveClientBoundsConfig();
 					runelite.shutdown();
+
+					if (SystemTray.isSupported())
+					{
+						SystemTray.getSystemTray().remove(trayIcon);
+					}
+
+					if (client != null)
+					{
+						client.stop();
+					}
+
+					if (client instanceof Client)
+					{
+						((Client)client).shutDown();
+					}
 				},
 				this::showWarningOnExit
 			);