formUnformat() { //FIXME test this
        const inputs = this.constructor._getChildANInputElement(this.form());
        inputs.forEach(input => {
            AutoNumeric.getAutoNumericElement(input).unformat();
        });

        return this;
    }
Unformat all the autoNumeric-managed elements that are a child of the parent <form> element of this DOM element, to numeric strings

@returns {AutoNumeric}