title: Readonly fields in the django admin/inline
body: <p>I use <a href="http://www.djangosnippets.org/snippets/937/" rel="noreferrer">this snippet</a> to show several fields in my admin backend as readonly, but as noticed in the comments, it does not work on stackedinline/tabularinline. Is there any other way to achieve this? I have a list of objects attached to a model and just want to show it in the model's details view without the possibility to change values.</p>