Move city-list data into a separate module

sky/examples/data/cities.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.
 -->
 <script>
-var cities = [
+module.exports = [
   {"name":"New York","state":"New York","population":8363710},
   {"name":"Los Angeles","state":"California","population":3833995},
   {"name":"Chicago","state":"Illinois","population":2853114},
   {"name":"Houston","state":"Texas","population":2242193},
   {"name":"Phoenix","state":"Arizona","population":1567924},
   {"name":"Philadelphia","state":"Pennsylvania","population":1447395},
   {"name":"San Antonio","state":"Texas","population":1351305},
   {"name":"Dallas","state":"Texas","population":1279910},
   {"name":"San Diego","state":"California","population":1279329},
   {"name":"San Jose","state":"California","population":948279},
@@ skipping 4980 matching lines @@
   {"name":"Chelsea","state":"Alabama","population":4303},
   {"name":"Blanchester","state":"Ohio","population":4303},
   {"name":"Waverly","state":"New York","population":4303},
   {"name":"Wolverine Lake","state":"Michigan","population":4303},
   {"name":"Jersey Shore","state":"Pennsylvania","population":4302},
   {"name":"Kenneth City","state":"Florida","population":4300},
   {"name":"Jenkintown","state":"Pennsylvania","population":4299},
   {"name":"Hartwell","state":"Georgia","population":4298},
   {"name":"Newport","state":"North Carolina","population":4298}
 ];
-
-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>