zmedia
Used for triggering the insertion of a media item in the TinyMCE editor in the admin.
The action opens _action_dialog_zmedia_choose.tpl. Its arguments are passed to
that dialog, including the current resource id, subject_id, and the editor's
media_div_id when supplied.
{% button text="Add media" action={zmedia id=id subject_id=id media_div_id="body-media"} %}
The chooser finishes through the internal zmedia_choose and
zmedia_has_chosen actions.