iterate with iterationNumber

[eMerzh]

In localforage, the iterate function contains an iteration number,
it can be handy and it shouldn't be that hard to add ...no?

https://mozilla.github.io/localForage/#iterate

Thanks

[scotttrinh]

Agreed. It should be API-compatible with localForage. Thanks for spotting it!

[scotttrinh]

@eMerzh
I looked into this a bit, and it seems like a documentation issue, as we just pass the callback directly to localForage, which should pass the same values to your callback as the unwrapped version. I'll write some unit tests and documentation.