#14 Comment Disabling on Archive

[Ben]

An option in "settings" to automatically set the "allow
comments" flag to false when entries drop into the
archive (i.e., when they're not displayed on the mail
page, or in the "recent entries" area.

This means that only current entries will be
commentable, so old entries in the archive will be read
only. Stops comment spam on old links.

This should be an option, initally disabled, as old
entries may still glean comments.