mod_admin/mod_admin_frontend: preparations to allow creation of resources via the edit page.

(cherry picked from commit fbcf7d8022ff0bbfa769588fccf329c372b23e5c)

Conflicts:
	modules/mod_admin/templates/_admin_edit_body.tpl
	modules/mod_admin_frontend/templates/_admin_frontend_edit.tpl
	modules/mod_admin_frontend/templates/page_admin_frontend_edit.tpl

(cherry picked from commit e8727727c65bb04cf76b1423b77ed5b769c20bc4)