(xterm--extra-capabilities-type): Add `getSelection'.
(xterm--query): Add `no-async' argument.
(xterm--init-activate-get-selection): New function.
(terminal-init-xterm): Use it.
(xterm--init-modify-other-keys): Rename from
terminal-init-xterm-modify-other-keys.
(xterm--init-bracketed-paste-mode): Rename from
terminal-init-xterm-bracketed-paste-mode.
(xterm--init-activate-set-selection): Rename from
terminal-init-xterm-activate-set-selection.
(xterm--selection-char): New function.
(gui-backend-set-selection): Use it.  Use the &context to only apply
this method in terminals where we enabled the feature.
(gui-backend-get-selection): New method.

* lisp/frame.el (gui-method--name, gui-method, gui-method-define)
(gui-method-declare, gui-call): Remove.
(frame-creation-function): Use cl-defgeneric.
(make-frame): Adjust callers.

* lisp/menu-bar.el (menu-bar-edit-menu):
Use gui-backend-selection-exists-p.

* lisp/select.el (x-get-clipboard): Use gui-backend-get-selection.
(gui-backend-get-selection): New cl-generic to replace
gui-get-selection method.
(gui-backend-set-selection): New cl-generic to replace
gui-set-selection method.
(gui-selection-owner-p): New cl-generic to replace
gui-selection-owner-p method.
(gui-backend-selection-exists-p): New cl-generic to replace
gui-selection-exists-p method.  Adjust all callers.

* lisp/server.el (server-create-window-system-frame): Don't ignore
window-system spec even when unsupported.

* lisp/simple.el (deactivate-mark): Use new gui-backend-* functions.

* lisp/startup.el (handle-args-function, window-system-initialization):
Use cl-defgeneric.
(command-line): Adjust calls accordingly.

* lisp/term/ns-win.el (ns-window-system-initialization): Turn into
a window-system-initialization method.
(handle-args-function, frame-creation-function): Use cl-defmethod.
(gui-set-selection, gui-selection-owner-p, gui-selection-exists-p)
(gui-get-selection): Use cl-defmethod on the new functions instead.

* lisp/term/pc-win.el (w16-get-selection-value): Turn into
a gui-backend-get-selection method.
(gui-selection-exists-p, gui-selection-owner-p, gui-set-selection):
Use cl-defmethod on the new functions instead.
(msdos-window-system-initialization): Turn into
a window-system-initialization method.
(frame-creation-function, handle-args-function): Use cl-defmethod.

* lisp/term/w32-win.el (w32-window-system-initialization): Turn into
a window-system-initialization method.
(handle-args-function, frame-creation-function): Use cl-defmethod.
(gui-set-selection, gui-selection-owner-p, gui-selection-exists-p)
(gui-get-selection): Use cl-defmethod on the new functions instead.

* lisp/term/x-win.el (x-window-system-initialization): Turn into
a window-system-initialization method.
(handle-args-function, frame-creation-function): Use cl-defmethod.
(gui-set-selection, gui-selection-owner-p, gui-selection-exists-p)
(gui-get-selection): Use cl-defmethod on the new functions instead.

* lisp/term/xterm.el (xterm--set-selection): Turn into
a gui-backend-set-selection method.

* src/nsselect.m (Fns_selection_exists_p): Remove unused arg `terminal'.
(Fns_selection_owner_p): Remove unused arg `terminal'.
(Fns_get_selection): Remove unused args `time_stamp' and `terminal'.

These were glitches regardless of how or whether we tackle the
problem of grave accent in doc strings.
* lisp/calc/calc-aent.el (math-restore-placeholders):
* lisp/ido.el (ido-ignore-buffers, ido-ignore-files):
* lisp/leim/quail/cyrillic.el ("bulgarian-alt-phonetic"):
* lisp/leim/quail/hebrew.el ("hebrew-new")
("hebrew-biblical-sil"):
* lisp/leim/quail/thai.el ("thai-kesmanee"):
* lisp/progmodes/idlw-shell.el (idlwave-shell-file-name-chars):
Used curved quotes to avoid ambiguities like ‘`''’ in doc strings.
* lisp/calendar/calendar.el (calendar-month-abbrev-array):
* lisp/cedet/semantic/mru-bookmark.el (semantic-mrub-cache-flush-fcn):
* lisp/cedet/semantic/symref.el (semantic-symref-tool-baseclass):
* lisp/cedet/semantic/tag.el (semantic-tag-copy)
(semantic-tag-components):
* lisp/cedet/srecode/cpp.el (srecode-semantic-handle-:cpp):
* lisp/cedet/srecode/texi.el (srecode-texi-texify-docstring):
* lisp/emacs-lisp/byte-opt.el (byte-optimize-all-constp):
* lisp/emacs-lisp/checkdoc.el (checkdoc-message-text-engine):
* lisp/emacs-lisp/generator.el (iter-next):
* lisp/gnus/gnus-art.el (gnus-treat-strip-list-identifiers)
(gnus-article-mode-syntax-table):
* lisp/net/rlogin.el (rlogin-directory-tracking-mode):
* lisp/net/soap-client.el (soap-wsdl-get):
* lisp/net/telnet.el (telnet-mode):
* lisp/org/org-compat.el (org-number-sequence):
* lisp/org/org.el (org-remove-highlights-with-change)
(org-structure-template-alist):
* lisp/org/ox-html.el (org-html-link-org-files-as-html):
* lisp/play/handwrite.el (handwrite-10pt, handwrite-11pt)
(handwrite-12pt, handwrite-13pt):
* lisp/progmodes/f90.el (f90-mode, f90-abbrev-start):
* lisp/progmodes/idlwave.el (idlwave-mode, idlwave-check-abbrev):
* lisp/progmodes/verilog-mode.el (verilog-tool)
(verilog-string-replace-matches, verilog-preprocess)
(verilog-auto-insert-lisp, verilog-auto-insert-last):
* lisp/textmodes/makeinfo.el (makeinfo-options):
* src/font.c (Ffont_spec):
Fix minor quoting problems in doc strings, e.g., missing quote,
``x'' where `x' was meant, etc.
* lisp/erc/erc-backend.el (erc-process-sentinel-2):
Fix minor quoting problem in other string.
* lisp/leim/quail/ethiopic.el ("ethiopic"):
* lisp/term/tvi970.el (tvi970-set-keypad-mode):
Omit unnecessary quotes.
* lisp/faces.el (set-face-attribute, set-face-underline)
(set-face-inverse-video, x-create-frame-with-faces):
* lisp/gnus/gnus-group.el (gnus-group-nnimap-edit-acl):
* lisp/mail/supercite.el (sc-attribs-%@-addresses)
(sc-attribs-!-addresses, sc-attribs-<>-addresses):
* lisp/net/tramp.el (tramp-methods):
* lisp/recentf.el (recentf-show-file-shortcuts-flag):
* lisp/textmodes/artist.el (artist-ellipse-right-char)
(artist-ellipse-left-char, artist-vaporize-fuzziness)
(artist-spray-chars, artist-mode, artist-replace-string)
(artist-put-pixel, artist-text-see-thru):
* lisp/vc/ediff-util.el (ediff-submit-report):
* lisp/vc/log-edit.el (log-edit-changelog-full-paragraphs):
Use double-quotes rather than TeX markup in doc strings.
* lisp/skeleton.el (skeleton-pair-insert-maybe):
Reword to avoid the need for grave accent and apostrophe.
* lisp/xt-mouse.el (xterm-mouse-tracking-enable-sequence):
Don't use grave and acute accents to quote.

* lisp/term/w32console.el (terminal-init-w32console): Repeat the
test for curved quotes being displayable, after switching the
terminal encoding.  (Bug#20545)

* lisp/term/rxvt.el: Require term/xterm.
(rxvt-function-map): Use xterm-rxvt-function-map.
(rxvt-standard-colors): Move before first use.
(terminal-init-rxvt): Use xterm--push-map and xterm-register-default-colors.
(rxvt-rgb-convert-to-16bit, rxvt-register-default-colors): Remove.

* lisp/term/xterm.el (xterm-rxvt-function-map): New var.
Move shared bindings between rxvt and xterm to it.
(xterm-function-map): Use it.  Move the xterm-paste binding to
xterm-rxvt-function-map (bug#20444).
(xterm-standard-colors): Move before first use.
(xterm--push-map): New function.
(xterm-register-default-colors): Take standard colors as argument.
(terminal-init-xterm): Use it.  Adjust call to
xterm-register-default-colors.

(x-own-selection-internal, x-disown-selection-internal)
(x-selection-owner-p, x-selection-exists-p, x-get-selection-internal):
Declare.

* lisp/term/common-win.el: Provide a feature.
* lisp/term/x-win.el (term/common-win): Require it.

* ns-win.el (ns-paste-secondary): Use gui-get-selection.

(terminal-init-screen): Use it (bug#20356).
* lisp/term/xterm.el: Provide `term/xterm' instead of `xterm'.
(xterm--extra-capabilities-type): New const.
(xterm-extra-capabilities): Use it.
(xterm--version-handler): Lower the pseudo-version for `screen'.

* lisp/term/ns-win.el (ns-get-cut-buffer-internal): Remove this alias.