Clean up examples directory

sky/examples/city-list/city-data-service.sky

-<!--
-// Copyright 2014 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
--->
-<import src="../data/cities.sky" as="cities" />
-<script>
-function CityDataService(cities) {
-  this.cities = cities;
-
-  // sort by state, city name.
-  this.cities.sort(function(a, b) {
-    if (a.state != b.state) {
-      return a.state < b.state ? -1 : 1;
-    }
-
-    return a.name < b.name ? -1 : 1;
-  });
-}
-
-CityDataService.prototype.get = function(index, count) {
-  var self = this;
-
-  return new Promise(function(fulfill) {
-    var result = [];
-    while (count-- > 0) {
-      while (index < 0) {
-        index += self.cities.length;
-      }
-      if (index >= self.cities.length)
-        index = index % self.cities.length;
-
-      result.push(self.cities[index]);
-      index++;
-    }
-
-    fulfill(result);
-  });
-}
-
-module.exports = {
-  service: new Promise(function(fulfill) {
-    fulfill(new CityDataService(cities));
-  })
-};
-</script>