anchor.diff:    "Pathname Entry -> nil
   After deleting the old pages in the Entry, parse the file and for each language, write the appropriate page. Update the entry to reflect this."
     (delete-old-pages entry)
  -  (let* ((*environment* (merge-environments
  -			 (parse-page (merge-pathnames file *content-dir*))
  -			 *environment*)))
  +  (let ((*environment* (merge-environments
  +			(parse-page (merge-pathnames file *content-dir*))
  +			*environment*)))
       (iter (for lang in (getf *environment* :languages))
  -	  (let ((*environment* (merge-environments (list :lang lang
  -							 :current-file (namestring file))
  -						   *environment*)))
  +	  (let ((*environment* (merge-environments
  +				(list :lang lang
  +				      :current-file (namestring file))
  +				*environment*)))
   	    (write-page (merge-pathnames (getf (content-entry-pages entry) lang)
   					 *site-dir*))))
       (setf (content-entry-needs-update entry) nil
  
positive.code:   "nil -> nil
  Perform the steps necessary to ensure that the database is up to date."
    (setf *templates* (walk-templates)
  	*dependants* nil)
    (walk-site *content-dir* nil nil)
    (resolve-dependencies))
  
  (defun walk-site (dir configs dir-slugs)
    "Pathname ((cons Pathname Timestamp)) Plist -> nil
  
negative.code:   "Pathspec ({(Pathname . Integer)}+) -> {(Pathname . Integer)}+
  Return the template located at PATH from a list TEMPLATES that is comprised of (pathname file-write-date) pairs."
    (find (pathname path) templates :key #'caar :test #'equal))
  
  (defun resolve-deleted-pages ()
    (iter (for (path _) in-hashtable *db*)
  	(unless (file-exists-p (merge-pathnames path *content-dir*))
  	  (file-moved? path))))
  
  (defun update-site (needs-update)
    "((Pathname Entry (Pathname))) -> nil
  