given a form html element, submit it with an XHR as if you had clicked submit, but without navigating the page.
sets all the necessary headers etc so that it looks like a regular form submit.
var submit = require('submit-form-element').submit
submit.($('form'), $('button'), function (err, response) {
//calls back error, or xhr response
})return a js object representing the data that would be submitted if you were to click this button.
submit the given form by clicking a particular button, and callback the response
MIT