Isolate fetchQueue instances

Previously we were aborting the upstream request if any pending calls triggered a bindToRoute cleanup. This caused issues when fetch+load calls were made on a single object as the load call would terminate the fetch call incorrectly.
Use _.indexOf rather than [].indexOf

IE8 apparently does not like [].indexOf
Updates per review
Merge pull request #372 from walmartlabs/load-abort

Isolate fetchQueue instances