Allow configuration of fetch method

[OliverJAsh]

In my Backbone app, I have written a function that sits on top of fetch and deals with things like params for me. I would be able to use this plugin if it allowed the configuration of not just the parameters in the fetch call, but total control over what function gets called. I should be able to use my custom method in place of fetch.

Would you consider adding this?

For reference, this is what I would like control over: https://github.com/joneath/infiniScroll.js/blob/master/lib/infiniScroll.js#L90-95

[david-crespo]

Instead of using a function on top of fetch, you could override it.