Added AVX2 support (#6)

* Added AVX2 support

compress_noasm.go

@@ -1,11 +1,20 @@
 //+build !amd64 noasm appengine
 
-// Written in 2012 by Dmitry Chestnykh.
-//
-// To the extent possible under law, the author have dedicated all copyright
-// and related and neighboring rights to this software to the public domain
-// worldwide. This software is distributed without any warranty.
-// http://creativecommons.org/publicdomain/zero/1.0/
+/*
+ * Minio Cloud Storage, (C) 2016 Minio, Inc.
+ *
+ * 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.
+ */
 
 package blake2b