RB.ResourceCollection was documenting and supporting the old-style way

of opting in/out of resetting the collection during fetch. Backbone

changed how this worked. We now support the modern way, and document it.
The modern way (Backbone.js 1.1+) is to use reset instead of remove.

Resetting is also opt-in in Backbone.js 1.1, though we flip that for

this collection to make it opt-out. We're not currently using

Backbone.js 1.1, but we want to stay close to this semantics to smooth

over the upgrade process.
It's also pretty useful to be able to specify the maximum number of

items to fetch in each batch. Callers could do this by passing

extraQueryData['max-results'], but that was less than ideal. There's now

a maxResults option that can be passed instead.
There's also fixes for the pagination indicators, hasNext and hasPrev,

which could appear as undefined depending on the payload.

Made use of this in some new code I'm working on.
Saw that I only got the number of results back that I requested when

using maxResults.
Saw the collection reset on each fetch, instead of just appending.
Unit tests pass.