* lisp/erc/erc*.el: Add J.P. as my comaintainer to headers.

Also remove various redundant `:group` arguments.

* lisp/erc/erc-backend.el (define-erc-response-handler): Move `declare`
after the docstring.

* lisp/erc/erc-capab.el: Use lexical-binding.
(erc-capab-identify-activate): Simplify with `member`.

* lisp/erc/erc-dcc.el (erc-dcc): Move before erc-dcc-mode definition,
which refers to it.
(erc-dcc-chat-accept): Remove unused vars `nick` and `buffer`.

* lisp/erc/erc-imenu.el: Use lexical-binding.
(erc-create-imenu-index): Remove unused var `prev-pos`.

* lisp/erc/erc-match.el: Use lexical-binding.
(erc-match-message): Remove unused var `old-pt`.
(erc-match-message): Strength-reduce `eval` to `symbol-value`.

* lisp/erc/erc-page.el: Use lexical-binding.
(erc-page): Move Custom group before `erg-page-mode` which refers to it.

* lisp/erc/erc-replace.el: Use lexical-binding.
(erc-replace-insert): Use `functionp`.

* lisp/erc/erc-status-sidebar.el: Use lexical-binding.
(erc-status-sidebar-open): Remove unused var `sidebar-window`.

* lisp/erc/erc.el: Fix header to use the customary 3 semi-colons.
(erc-fill-column): Declare variable.

* lisp/erc/erc-autoaway.el: Use lexical-binding.
* lisp/erc/erc-ezbounce.el: Use lexical-binding.
* lisp/erc/erc-fill.el: Use lexical-binding.
* lisp/erc/erc-goodies.el: Use lexical-binding.
* lisp/erc/erc-ibuffer.el: Use lexical-binding.
* lisp/erc/erc-identd.el: Use lexical-binding.
* lisp/erc/erc-join.el: Use lexical-binding.
* lisp/erc/erc-lang.el: Use lexical-binding.
* lisp/erc/erc-log.el: Use lexical-binding.
* lisp/erc/erc-menu.el: Use lexical-binding.
* lisp/erc/erc-netsplit.el: Use lexical-binding.
* lisp/erc/erc-networks.el: Use lexical-binding.
* lisp/erc/erc-pcomplete.el: Use lexical-binding.
* lisp/erc/erc-ring.el: Use lexical-binding.
* lisp/erc/erc-speedbar.el: Use lexical-binding.
* lisp/erc/erc-spelling.el: Use lexical-binding.
* lisp/erc/erc-truncate.el: Use lexical-binding.
* lisp/erc/erc-xdcc.el: Use lexical-binding.

* admin/charsets/mapfiles/README:
* doc/emacs/custom.texi (Saving Customizations):
* doc/lispintro/emacs-lisp-intro.texi (Simple Extension):
* doc/misc/efaq-w32.texi (Location of init file):
* doc/misc/gnus-faq.texi (FAQ 1-3):
* doc/misc/gnus.texi (Top, Various, Image Enhancements):
* lisp/erc/erc-menu.el (menu):
* lisp/progmodes/cfengine.el (cfengine-fill-paragraph):
Remove some references to Emacs 22 and earlier.

* doc/lispref/buffers.texi:
* doc/lispref/eval.texi:
* doc/lispref/files.texi:
* doc/lispref/keymaps.texi:
* doc/lispref/loading.texi:
* doc/lispref/minibuf.texi:
* doc/lispref/positions.texi:
* doc/lispref/variables.texi: Remove comments about "Emacs 19
specific" features.

* lisp/allout.el:
* lisp/emacs-lisp/edebug.el:
* lisp/emacs-lisp/ert.el:
* lisp/erc/erc-menu.el:
* lisp/help-mode.el:
* lisp/net/dictionary.el:
* lisp/nxml/rng-nxml.el:
* lisp/progmodes/ebrowse.el:
* lisp/progmodes/meta-mode.el:
* lisp/progmodes/prolog.el:
* lisp/progmodes/ps-mode.el:
* lisp/progmodes/vera-mode.el:
* lisp/wid-browse.el: Remove redundant require of easymenu.  We only
use the autoloaded macro 'easy-menu-define' here.

* lisp/erc/erc-backend.el:
* lisp/erc/erc-button.el:
* lisp/erc/erc-dcc.el:
* lisp/erc/erc-identd.el:
* lisp/erc/erc-join.el:
* lisp/erc/erc-lang.el:
* lisp/erc/erc-log.el:
* lisp/erc/erc-match.el:
* lisp/erc/erc-menu.el:
* lisp/erc/erc-pcomplete.el:
* lisp/erc/erc-replace.el:
* lisp/erc/erc-spelling.el:
* lisp/erc/erc-stamp.el:
* lisp/erc/erc-track.el:
* lisp/erc/erc-xdcc.el: Remove irrelevant entries in Keywords header.

Run "TZ=UTC0 admin/update-copyright".