[Issue #14] Remove jquery-mockjax requirement

you make a good point about the race conditions that mockjax only creates. however, it's practically impossible for that to happen. assuming the ajax call is a GET, the response should be the same assuming a correctly implemented api.

there is another bug where if you do two calls to the same endpoint during a request, there is no concept of "mock this call this many times".

Syncing is an internal-to-the-library tool. users will interact with Backbone sync in the standard way - they override the sync method