The styling of labels on the form largely obsoleted the special styled ol,
so just a few br's sufficed. Using an ol like that was not too semantically
right (probably?) and could cause problems with customized local.css.
Rationalle: Comments need to be user-editable so that they can be posted
via git commit etc.
The _comment directive is still supported, for back-compat.
Mostly to make it more visually similar to the page edit form.
I'm a bit uncertian about the placement of the page type selector,
and about removing the "Page type". May rethink that.