Fix a couple of doc comment references - and many spelling mistakes

sdk/lib/async/zone.dart

 // Copyright (c) 2013, 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.
 
 part of dart.async;
 
 typedef R ZoneCallback<R>();
 typedef R ZoneUnaryCallback<R, T>(T arg);
 typedef R ZoneBinaryCallback<R, T1, T2>(T1 arg1, T2 arg2);
 
@@ skipping 516 matching lines @@
    *      if (runGuarded) {
    *        return (arg1, arg2) => this.runBinaryGuarded(registered, arg);
    *      }
    *      return (arg1, arg2) => thin.runBinary(registered, arg1, arg2);
    */
   ZoneBinaryCallback<R, T1, T2> bindBinaryCallback<R, T1, T2>(
       R action(T1 argument1, T2 argument2),
       {bool runGuarded: true});
 
   /**
-   * Intercepts errors when added programatically to a `Future` or `Stream`.
+   * Intercepts errors when added programmatically to a `Future` or `Stream`.
    *
    * When calling [Completer.completeError], [StreamController.addError],
    * or some [Future] constructors, the current zone is allowed to intercept
    * and replace the error.
    *
    * Future constructors invoke this function when the error is received
    * directly, for example with [Future.error], or when the error is caught
    * synchronously, for example with [Future.sync].
    *
    * There is no guarantee that an error is only sent through [errorCallback]
@@ skipping 912 matching lines @@
         handleUncaughtError: errorHandler);
   }
   Zone zone = Zone.current
       .fork(specification: zoneSpecification, zoneValues: zoneValues);
   if (onError != null) {
     return zone.runGuarded(body);
   } else {
     return zone.run(body);
   }
 }