Remove reference to akka code and ArrayDeque which is not part of netty anymore

Motivation:

We not ship any forked code of akka and ArrayDeque anymore.

Modifications:

Remove reference from NOTICE.txt and license folder.

Result:

Correctly document license related things.

NOTICE.txt

@@ -58,12 +58,6 @@ facade for Java, which can be obtained at:
   * HOMEPAGE:
     * http://www.slf4j.org/
 
-This product contains a modified portion of 'ArrayDeque', written by Josh
-Bloch of Google, Inc:
-
-  * LICENSE:
-    * license/LICENSE.deque.txt (Public Domain)
-
 This product contains a modified portion of 'Apache Harmony', an open source
 Java SE, which can be obtained at:
 
@@ -72,15 +66,6 @@ Java SE, which can be obtained at:
   * HOMEPAGE:
     * http://archive.apache.org/dist/harmony/
 
-This product contains a modified version of Roland Kuhn's ASL2
-AbstractNodeQueue, which is based on Dmitriy Vyukov's non-intrusive MPSC queue.
-It can be obtained at:
-
-  * LICENSE:
-    * license/LICENSE.abstractnodequeue.txt (Public Domain)
-  * HOMEPAGE:
-    * https://github.com/akka/akka/blob/master/akka-actor/src/main/java/akka/dispatch/AbstractNodeQueue.java
-
 This product contains a modified portion of 'jbzip2', a Java bzip2 compression
 and decompression library written by Matthew J. Francis. It can be obtained at:
 

license/LICENSE.abstractnodequeue.txt

@@ -1,15 +0,0 @@
-This software is licensed under the Apache 2 license, quoted below.
-
-Copyright 2009-2013 Typesafe Inc. [http://www.typesafe.com]
-
-Licensed under the Apache License, Version 2.0 (the "License"); you may not
-use this file except in compliance with the License. You may obtain a copy of
-the License at
-
-    [http://www.apache.org/licenses/LICENSE-2.0]
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
-WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
-License for the specific language governing permissions and limitations under
-the License.

license/LICENSE.deque.txt

@@ -1,26 +0,0 @@
-The person or persons who have associated work with this document (the
-"Dedicator" or "Certifier") hereby either (a) certifies that, to the best of
-his knowledge, the work of authorship identified is in the public domain of
-the country from which the work is published, or (b) hereby dedicates whatever
-copyright the dedicators holds in the work of authorship identified below (the
-"Work") to the public domain. A certifier, moreover, dedicates any copyright
-interest he may have in the associated work, and for these purposes, is
-described as a "dedicator" below.
-
-A certifier has taken reasonable steps to verify the copyright status of this
-work. Certifier recognizes that his good faith efforts may not shield him from
-liability if in fact the work certified is not in the public domain.
-
-Dedicator makes this dedication for the benefit of the public at large and to
-the detriment of the Dedicator's heirs and successors. Dedicator intends this
-dedication to be an overt act of relinquishment in perpetuate of all present
-and future rights under copyright law, whether vested or contingent, in the
-Work. Dedicator understands that such relinquishment of all rights includes
-the relinquishment of all rights to enforce (by lawsuit or otherwise) those
-copyrights in the Work.
-
-Dedicator recognizes that, once placed in the public domain, the Work may be
-freely reproduced, distributed, transmitted, used, modified, built upon, or
-otherwise exploited by anyone for any purpose, commercial or non-commercial,
-and in any way, including by methods that have not yet been invented or
-conceived.