Issue title: Limit to number of ids on GET
 Issue body: When loading data for a large number of hasMany models, sometimes the GET request that is sent is extremely long.  Some browsers and servers have a maximum data length that you can send.

There should be a configurable option to ember-data that allows you to set the maxByteSize for a request.

 Comments: 
 Comment 0: @Mochaleaf did you mean to open this for ember-data instead of here?

 Comment 1: Sorry.. I did.  Will close and reopen over there

{'source': 'GithubIssues', 'repo_name_with_owner': 'emberjs/ember.js', 'issue_id': 4428146, 'repo_stars': 22327.0}