* src/keyboard.c (syms_of_keyboard):
<multiple_terminals_merge_keyboards>: New variable.
(read_event_from_main_queue): Mention it in message.
* lisp/cus-start.el: Make it customizable.
* src/callint.c (Ffuncall_interactively):
* src/keyboard.c (Frecursive_edit):
* src/minibuf.c (read_minibuf): When its value is true, don't
enter single-kboard mode (bug#79892).
* admin/notes/multi-tty:
* etc/NEWS: Document it.

Also, document stuffing better.
* src/keyboard.c (stuff_buffered_input):
Give up on stuffing if it fails.
* src/sysdep.c (stuff_char): Return failure indication.

* src/keyboard.c (kbd_buffer_get_event): Pass the event's frame
up to the caller by means of a new 'struct frame **' argument.
(read_event_from_main_queue): Show a message in locked frames in
single-kboard mode (bug#79892).
* src/xdisp.c (log_message): Factor out of message3.
(message3): Call it.
(message3_nolog): Rename to ...
(message3_frame_nolog): ... this.  New 'struct frame *' argument
which causes temporarily switching to another frame when
displaying the message.
(message3_frame, message3_nolog): New functions.
* src/lisp.h: Declare message3_frame and message3_frame_nolog.
* admin/notes/multi-tty: Remove notes on showing a message.

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

* admin/notes/multi-tty:
* doc/emacs/building.texi (Debugger Operation):
* doc/misc/efaq-w32.texi (Line ends by file system):
* doc/misc/gnus.texi (Hashcash):
* lisp/emacs-lisp/eieio.el (eieio-class-parents)
(eieio-class-children):
* lisp/progmodes/perl-mode.el:
* lisp/textmodes/ispell.el (ispell-lookup-words):
* src/buffer.h: Update or delete references to variables and functions
made obsolete in Emacs 24.4.

* admin/notes/multi-tty:
* lisp/chistory.el (command-history):
* lisp/emacs-lisp/nadvice.el:
* lisp/vc/diff-mode.el: Doc fix; don't refer to obsolete variables and
functions.