getListData
Retrieves list of records for the given set.
    function(set)
  
  Returns a promise that resolves to a ListData for a particular set.
connection.getListData({complete: true}).then(function(listData){
    connection.hydrateList(listData);
});
  
  Parameters
- set 
{Set}:A object that represents the set of data needed to be loaded. For example,
{complete: true}might represent the set of all completed records. 
Use
Extensions like data/url make it easy to implement getListData, but it can be as simple as:
var connection = connect([],{
  getListData: function(set){
    return new Promise(function(resolve, reject){
        $.get("/api/todos",set).then(resolve, reject)
    });
  }
})