We were adding <div> tags with the `images` or `documents` HTML class
prettly much every time we rendered a NestedComponent. We're now
including the HTML class inside the component, as we usually do.
We're also rendering the nested components directly, since it's been a
while since the partials were changed to simply render the components.
Note that the `create` action doesn't create an image but updates an
answer instead. We're removing the references to `:create` in the
abilities since it isn't used.
In the future we might change the form to add an image to an answer
because it's been broken for ages since it shows all the attached
images.
Since we were creating a new answer in the form, we weren't getting the
errors associated to the answer the administrator was trying to create,
and so we were skipping the test.
Using the answer which contains the information about validation errors
fixes the issue and so we don't have to skip the tests.
The imageable/documentable object is always the object the form builder
is based on; since we're already passing the form builder, we don't have
to pass the object as well.
The only exception are the poll answers. In this case, we're passing a
new answer as the object. That's OK; the same hack that we're using to
send the data to the answer URL without displaying existing attachments
causes the form to keep working the same way.
