* lisp/obsolete: Use lexical-binding

* lisp/obsolete: Use lexical-binding

Use lexical-binding in all the lisp/obsolete/*.el files.
While at it, removed redundant :group arguments and used #' to quote
functions.  Commented out the key bindings which the #' revealed
to lead to non-existing commands, and replaced those revealed to be obsolete.

* lisp/obsolete/cl-compat.el: Use cl-lib.

* lisp/obsolete/cust-print.el: Assume `defalias` exists.
(with-custom-print): Use `declare`.

* lisp/obsolete/iswitchb.el (iswitchb-init-XEmacs-trick)
(iswitchb-xemacs-backspacekey): Remove functions.

* lisp/obsolete/landmark.el (landmark, landmark-nslify-wts):
Prefer `apply` to `eval`.

* lisp/obsolete/longlines.el (longlines-mode): Don't use `add-to-list`
on a hook.

* lisp/obsolete/pgg-gpg.el (pgg-gpg-process-region): Use `clear-string`.

* lisp/obsolete/pgg-pgp.el (pgg-pgp-encrypt-region): Remove oddly
unused var `passphrase`.
(pgg-pgp-verify-region): Declare var `jam-zcat-filename-list`.

* lisp/obsolete/pgg-pgp5.el (pgg-pgp5-encrypt-region): Remove oddly
unused var `passphrase`.
(pgg-pgp5-verify-region): Declare var `jam-zcat-filename-list`.

* lisp/obsolete/pgg.el: Remove some XEmacs compatibility code.
(pgg-run-at-time, pgg-cancel-timer, pgg-clear-string): Remove functions.
Use their core equivalent instead.

* lisp/obsolete/rcompile.el (remote-compile): Remove unused vars `l`,
`l-host`, `l-user`, and `localname`.

* lisp/obsolete/starttls.el (starttls-any-program-available):
Use `define-obsolete-function-alias`.

* lisp/obsolete/tls.el (tls-format-message): Delete function, use
`format-message` instead.

* lisp/obsolete/url-ns.el (url-ns-prefs): Use `with-current-buffer`
and `dlet`.

* lisp/obsolete/vip.el (vip-escape-to-emacs): Remove unused var `key`.
(vip-command-argument, vip-read-string, ex-delete, ex-line): Remove
unused var `conditions`.
(ex-map): Use a closure instead of `eval`.
(ex-set): Make it an alias of `set-variable`.
(ex-substitute): Remove unused var `cont`.

* lisp/obsolete/abbrevlist.el:
* lisp/obsolete/bruce.el:
* lisp/obsolete/cc-compat.el:
* lisp/obsolete/cl-compat.el:
* lisp/obsolete/cl.el:
* lisp/obsolete/complete.el:
* lisp/obsolete/crisp.el:
* lisp/obsolete/cust-print.el:
* lisp/obsolete/erc-compat.el:
* lisp/obsolete/erc-hecomplete.el:
* lisp/obsolete/eudcb-ph.el:
* lisp/obsolete/fast-lock.el:
* lisp/obsolete/gs.el:
* lisp/obsolete/gulp.el:
* lisp/obsolete/html2text.el:
* lisp/obsolete/info-edit.el:
* lisp/obsolete/iswitchb.el:
* lisp/obsolete/landmark.el:
* lisp/obsolete/lazy-lock.el:
* lisp/obsolete/longlines.el:
* lisp/obsolete/mailpost.el:
* lisp/obsolete/mantemp.el:
* lisp/obsolete/meese.el:
* lisp/obsolete/messcompat.el:
* lisp/obsolete/metamail.el:
* lisp/obsolete/mouse-sel.el:
* lisp/obsolete/nnir.el:
* lisp/obsolete/old-emacs-lock.el:
* lisp/obsolete/otodo-mode.el:
* lisp/obsolete/patcomp.el:
* lisp/obsolete/pc-mode.el:
* lisp/obsolete/pc-select.el:
* lisp/obsolete/pgg-def.el:
* lisp/obsolete/pgg-gpg.el:
* lisp/obsolete/pgg-parse.el:
* lisp/obsolete/pgg-pgp.el:
* lisp/obsolete/pgg-pgp5.el:
* lisp/obsolete/pgg.el:
* lisp/obsolete/rcompile.el:
* lisp/obsolete/s-region.el:
* lisp/obsolete/sb-image.el:
* lisp/obsolete/sregex.el:
* lisp/obsolete/starttls.el:
* lisp/obsolete/sup-mouse.el:
* lisp/obsolete/terminal.el:
* lisp/obsolete/tls.el:
* lisp/obsolete/tpu-edt.el:
* lisp/obsolete/tpu-extras.el:
* lisp/obsolete/tpu-mapper.el:
* lisp/obsolete/url-ns.el:
* lisp/obsolete/vc-arch.el:
* lisp/obsolete/vi.el:
* lisp/obsolete/vip.el:
* lisp/obsolete/ws-mode.el:
* lisp/obsolete/yow.el: Use lexical-binding.