Prefer ‘time-equal-p’ to ‘equal’ on timestamps

Prefer ‘time-equal-p’ to ‘equal’ on timestamps

This is more robust since timestamps can have multiple forms.
* lisp/auth-source.el (auth-source-netrc-parse):
* lisp/bookmark.el (bookmark--watch-file-already-queried-p)
(bookmark-maybe-load-default-file):
* lisp/cedet/semantic/db.el (semanticdb-needs-refresh-p):
* lisp/dired.el (dired-directory-changed-p):
* lisp/files.el (dir-locals-find-file):
* lisp/gnus/gnus-util.el (gnus-cache-file-contents):
* lisp/gnus/nneething.el (nneething-create-mapping):
* lisp/gnus/nnfolder.el (nnfolder-read-folder):
* lisp/gnus/nnmaildir.el (nnmaildir--update-nov)
(nnmaildir--scan, nnmaildir-request-scan)
(nnmaildir-request-update-info):
* lisp/gnus/nnmh.el (nnmh-update-gnus-unreads):
* lisp/gnus/spam-stat.el (spam-stat-load):
* lisp/mail/mailabbrev.el (mail-abbrevs-sync-aliases):
* lisp/mail/sendmail.el (sendmail-sync-aliases):
* lisp/net/netrc.el (netrc-parse):
* lisp/nxml/rng-loc.el (rng-get-parsed-schema-locating-file):
* lisp/play/cookie1.el (cookie-snarf):
* lisp/vc/vc-cvs.el (vc-cvs-state-heuristic):
* lisp/vc/vc-hg.el (vc-hg--ignore-patterns-valid-p)
(vc-hg--cached-dirstate-search):
* lisp/vc/vc-hooks.el (vc-after-save):
Prefer ‘time-equal-p’ to ‘equal’ when comparing
timestamps for equality.