Support for pagination, and selective rollback for single attribute

[mtheoryx]

Enabled pagination of store

For example, a document model:

name: EG.attr({
  type: 'string'
});

Constructing a query for the store:

const query = {
  limit: 10,
  offset: 2
}

Will allow constructing a get request with query params so a backend server can correctly serve up just 10 documents.

You can also get the total (for pagination UI controls, next/last, X of Y, from the new property:

payload.meta.serverMeta

Selective rollback

Instead of doing a rollback on everything, a single attribute can be rolled back:

object.rollbackSingleAttribute(attribute);

[deleter8]

Looks good

[gordonkristan]

This would be a pretty big breaking change to the API. PromiseArray extends ArrayProxy which extends Ember.Object. If you want, you could just set a meta property on the array (or something similar). This would allow the return value of a query to jive well with templates. Up to you guys though, I'm not sure what your use cases are.

[gordonkristan]

There's also the Ember.meta function, which will probably work. I can't remember exactly how it works, but I know I've used it before. 😄