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

sdk/lib/collection/iterable.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.
 
 part of dart.collection;
 
 /**
  * This [Iterable] mixin implements all [Iterable] members except `iterator`.
  *
  * All other methods are implemented in terms of `iterator`.
@@ skipping 262 matching lines @@
 
 /** Check if we are currently visiting `o` in a toString call. */
 bool _isToStringVisiting(Object o) {
   for (int i = 0; i < _toStringVisiting.length; i++) {
     if (identical(o, _toStringVisiting[i])) return true;
   }
   return false;
 }
 
 /**
- * Convert elments of [iterable] to strings and store them in [parts].
+ * Convert elements of [iterable] to strings and store them in [parts].
  */
 void _iterablePartsToStrings(Iterable iterable, List parts) {
   /*
    * This is the complicated part of [iterableToShortString].
    * It is extracted as a separate function to avoid having too much code
    * inside the try/finally.
    */
   /// Try to stay below this many characters.
   const int LENGTH_LIMIT = 80;
 
@@ skipping 95 matching lines @@
       elision = "...";
       length += ELLIPSIS_SIZE + OVERHEAD;
     }
   }
   if (elision != null) {
     parts.add(elision);
   }
   parts.add(penultimateString);
   parts.add(ultimateString);
 }