Functional test:

    >>> app = layer['app']
    >>> portal = layer['portal']
    >>> request = layer['request']

    >>> from plone.testing.z2 import Browser
    >>> browser = Browser(app)
    >>> portalURL = portal.absolute_url()

    >>> from plone.app.testing import SITE_OWNER_NAME, SITE_OWNER_PASSWORD
    >>> browser.open(portalURL + '/login_form')
    >>> browser.getControl(name='__ac_name').value = SITE_OWNER_NAME
    >>> browser.getControl(name='__ac_password').value = SITE_OWNER_PASSWORD
    >>> browser.getControl(name='submit').click()

    >>> 'You are now logged in' in browser.contents
    True

    >>> browser.open(portalURL + '/@@test-collective-z3cform-widgets')

XXX: Test the demo form
