Add a way to skip the plugin verifier.

ProtocolLib/src/main/java/com/comphenix/protocol/events/ListenerOptions.java

@@ -19,6 +19,11 @@ public enum ListenerOptions {
 	 */
 	DISABLE_GAMEPHASE_DETECTION,
 	
+	/**
+	 * Do not verify that the owning plugin has a vaid plugin.yml.
+	 */
+	SKIP_PLUGIN_VERIFIER,
+	
 	/**
 	 * Notify ProtocolLib that {@link PacketListener#onPacketSending(PacketEvent)} is thread safe.
 	 */

ProtocolLib/src/main/java/com/comphenix/protocol/injector/PacketFilterManager.java

@@ -23,7 +23,6 @@ import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 import java.util.Set;
-import java.util.concurrent.Callable;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicInteger;
@@ -402,15 +401,19 @@ public final class PacketFilterManager implements ProtocolManager, ListenerInvok
 		
 		// A listener can only be added once
 		if (packetListeners.contains(listener))
-			return;
-		// Check plugin
-		printPluginWarnings(listener.getPlugin());
-		
+			return;		
 		ListeningWhitelist sending = listener.getSendingWhitelist();
 		ListeningWhitelist receiving = listener.getReceivingWhitelist();
 		boolean hasSending = sending != null && sending.isEnabled();
 		boolean hasReceiving = receiving != null && receiving.isEnabled();
 		
+		// Check plugin
+		if (!(hasSending && sending.getOptions().contains(ListenerOptions.SKIP_PLUGIN_VERIFIER)) &&
+			!(hasReceiving && receiving.getOptions().contains(ListenerOptions.SKIP_PLUGIN_VERIFIER))) {
+			
+			printPluginWarnings(listener.getPlugin());
+		}
+		
 		if (hasSending || hasReceiving) {
 			// Add listeners and hooks
 			if (hasSending) {