Minor cleanup for times as lists of four integers.

Minor cleanup for times as lists of four integers.

* doc/lispref/os.texi (Time Parsing): Time values can now be four integers.
* lisp/files.el (dir-locals-directory-cache):
* lisp/ps-bdf.el (bdf-file-mod-time, bdf-read-font-info):
Doc fixes.
* lisp/net/tramp-sh.el (tramp-do-file-attributes-with-ls):
* lisp/ps-bdf.el (bdf-file-newer-than-time):
Process four-integers time stamps, not two.  Doc fixes.