Remove Collection, Collections and clean up List/Set/Queue implementations of retain/remove.

pkg/unittest/test/matchers_test.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 unittestTests;
 import 'package:unittest/unittest.dart';
 import 'dart:async';
 import 'dart:collection';
 part 'test_utils.dart';
 
@@ skipping 443 matching lines @@
       shouldFail(e, isEmpty, "Expected: empty but: was <[1]>.");
     });
     
     test('contains', () {
       var d = new SimpleIterable(3);
       shouldPass(d, contains(2));
       shouldFail(d, contains(5), "Expected: contains <5> but: was <[3]>.");
     });
   });
   
-  group('Collection Matchers', () {
+  group('Iterable Matchers', () {
 
     test('isEmpty', () {
       shouldPass([], isEmpty);
       shouldFail([1], isEmpty, "Expected: empty but: was <[1]>.");
     });
 
     test('contains', () {
       var d = [1, 2];
       shouldPass(d, contains(1));
       shouldFail(d, contains(0), "Expected: contains <0> but: was <[1, 2]>.");
@@ skipping 228 matching lines @@
       var w = new Widget();
       w.price = 10;
       shouldPass(w, new HasPrice(greaterThan(0)));
       shouldFail(w, new HasPrice(greaterThan(10)),
           'Expected: Widget with a price that is a value greater than <10> '
           'but: price was <10>.');
     });
   });
 }