[Promise] Y.batch should accept and flatten nested arrays

[ericf]

Y.batch() would be much more useful if it accepted arguments which were arrays as well. It could take its arguments and flatten any arrays into one array using Y.Array.flatten()

[juandopazo]

At #670 we're working on deprecating Y.batch in favor of Y.Promise.every which takes an array.

[juandopazo]

I was hoping to leave Y.Promise.every as an implementation of the DOM standard, and I don't see the DOM flattening arrays. I think the most compelling reason to flatten would be, in the case of batch, to be able to pass multiple arguments and alternatively an array, just like use() does. But since Promise.every only takes an array it seems unnecessary to flatten. What do you think?

[lsmith]

-1 to flattening. Follow the emerging spec. Devs can flatten the input array if they need to.

[ericf]

Yeah that's fine, I didn't realize there was a spec emerging for this. I can use Y.Array.flatten() when I hit this.