Add server based pagination support

Automatically discover paginated results by looking for a `results` array
in the response from djang-rest-framework. If results are paginated, create
a `pagination` object in the metadata. This `pagination` object contains :
- count: total number of objects
- current: current page number
- previous: previous page number, or false
- next: next page number, or false

To use the `pagination` object in your controller, you can define a new Mixin
and add it to your controller.

App.PaginationMixins = Ember.Mixin.create({
    pagination: function() {
        if(this.get('model.isLoaded')) {
            var modelType = this.get('model.type');
            return this.get('store').typeMapFor(modelType).metadata.pagination;
        }
    }.property('model.isLoaded'),
});

Define some routes:

App.Router.map(function() {
    this.resource('myobjects', { path: '/myobjects' }, function() {
        this.route('page', {path: '/page/:page'});
    };
});

App.MyobjectsIndexRoute = Ember.Route.extend({
    redirect: function() {
        this.transitionTo('myobjects.page', 1);
    },
});

App.MyobjectsPageRoute = Ember.Route.extend({
    model: function(params) {
        return App.Object.find({page: params.page});
    },
});

In your template:

{{#if pagination.next}}
  {{#linkTo 'myobjects.page' pagination.next}}next{{/linkTo}}
{{/if}}
Add unit testing for server based pagination
Merge pull request #33 from lmeunier/pagination

Add server based pagination support