Implement equals() and hashCode(), since we've implemented compareTo.

ProtocolLib/src/main/java/com/comphenix/protocol/async/AsyncMarker.java

@@ -32,6 +32,7 @@ import com.comphenix.protocol.events.PacketEvent;
 import com.comphenix.protocol.injector.PrioritizedListener;
 import com.comphenix.protocol.reflect.FieldAccessException;
 import com.comphenix.protocol.reflect.FuzzyReflection;
+import com.google.common.base.Objects;
 import com.google.common.primitives.Longs;
 
 /**
@@ -447,4 +448,22 @@ public class AsyncMarker implements Serializable, Comparable<AsyncMarker> {
 		else
 			return Longs.compare(getNewSendingIndex(), o.getNewSendingIndex());
 	}
+	
+	@Override
+	public boolean equals(Object other) {
+		// Standard equals
+		if (other == this)
+			return true;
+		if (other == null)
+			return false;
+		if (other instanceof AsyncMarker)
+			return Objects.equal(getNewSendingIndex(), ((AsyncMarker) other).getNewSendingIndex());
+		
+		return false;
+	}
+	
+	@Override
+	public int hashCode() {
+		return Longs.hashCode(getNewSendingIndex());
+	}
 }