Add params to Ember Data's RESTAdapter AJAX requests.

ember-data-global-ajax-params.js

App.accountId = 'asdf';

App.RESTAdapter = DS.RESTAdapter.extend({
  // Scope all ajax calls.
  ajax: function(url, type, hash) {
    if (Ember.isEmpty(hash)) hash = {};
    if (Ember.isEmpty(hash.data)) hash.data = {};
    hash.data.account_id = App.accountId;
    this._super(url, type, hash);
  }
});

App.Store = DS.Store.extend({
  revision: 12,
  adapter: "App.RESTAdapter"
});