Deprecate Math object in corelib in favor of dart:math library.

lib/crypto/crypto.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #library('dart:crypto');
 
+#import('dart:math');
+
 #source('crypto_utils.dart');
 #source('hash_utils.dart');
 #source('hmac.dart');
 #source('md5.dart');
 #source('sha1.dart');
 #source('sha256.dart');
 
 /**
  * Interface for cryptographic hash functions.
  *
@@ skipping 103 matching lines @@
 /**
  * HashExceptions are thrown on invalid use of a Hash
  * object.
  */
 class HashException {
   HashException(String this.message);
   toString() => "HashException: $message";
   String message;
 }