A Backbone collection with paging and simple caching capabilities

var collection = new Backbone.PagedCollection(models, [options]);

PagedCollection accepts the same options as Backbone.Collection, with the following additions:
perPage: number of items to display per page, defaults to 10.
collection: type of collection to use as the page collection, defaults to Backbone.Collection. cacheFunction: a function which accepts a timestamp and should return true if the page should be re-fetched, or false otherwise.

There's an optional collection.filter() function, which accepts an object of key-values, resets the collection and passes the filter object as the data in the Backbone.sync requests.

The fetch() function may also accept the same options as with a normal collection, with the following addition: force: when true, will fetch the current page from the server without regard to it being cached.

PagedCollection expects server responses to be of the following format:

{
  total: [total],
  per_page: [per_page],
  page: [current_page],
  items: [array_of_items]
}