Multibyte characters on chunk boundaries get corrupted.

test/specs/requests.spec.js
var rejectSpy = jasmine.createSpy('reject');
    axios('/foo', {
      validateStatus: function (status) {
        return status === 500;
      }
    }).then(resolveSpy)
      .catch(rejectSpy)
      .then(function () {
        expect(resolveSpy).toHaveBeenCalled();
        expect(rejectSpy).not.toHaveBeenCalled();
        done();
      });
    getAjaxRequest().then(function (request) {
      request.respondWith({
        status: 500
      });
    });
  });
  it('should resolve when the response status is 0 (i.e. requesting with file protocol)', function (done) {
    var resolveSpy = jasmine.createSpy('resolve');
    var rejectSpy = jasmine.createSpy('reject');
    axios('file:///xxx').then(resolveSpy)
      .catch(rejectSpy)
      .then(function () {
        expect(resolveSpy).toHaveBeenCalled();
        expect(rejectSpy).not.toHaveBeenCalled();
        done();
      });
    getAjaxRequest().then(function (request) {
      request.respondWith({