Fixes related to select-enable-clipboard

* lisp/menu-bar.el (clipboard-yank, clipboard-kill-ring-save)
(clipboard-kill-region):
* lisp/eshell/esh-io.el (eshell-virtual-targets)
(eshell-clipboard-append):
Replace option gui-select-enable-clipboard with
select-enable-clipboard; renamed October 2014.  (Bug#25145)

lisp/eshell/esh-io.el

@@ -125,7 +125,7 @@ from executing while Emacs is redisplaying."
 		   'eshell-kill-append) t)
     ("/dev/clip" (lambda (mode)
 		   (if (eq mode 'overwrite)
-		       (let ((gui-select-enable-clipboard t))
+		       (let ((select-enable-clipboard t))
 			 (kill-new "")))
 		   'eshell-clipboard-append) t))
   "Map virtual devices name to Emacs Lisp functions.
@@ -325,7 +325,7 @@ last execution result should not be changed."
 (defun eshell-clipboard-append (string)
   "Call `kill-append' with STRING, if it is indeed a string."
   (if (stringp string)
-      (let ((gui-select-enable-clipboard t))
+      (let ((select-enable-clipboard t))
 	(kill-append string nil))))
 
 (defun eshell-get-target (target &optional mode)

lisp/menu-bar.el

@@ -530,12 +530,10 @@
                             (gui-backend-selection-exists-p 'CLIPBOARD))
                         (not buffer-read-only)))))
 
-(defvar gui-select-enable-clipboard)
-
 (defun clipboard-yank ()
   "Insert the clipboard contents, or the last stretch of killed text."
   (interactive "*")
-  (let ((gui-select-enable-clipboard t))
+  (let ((select-enable-clipboard t))
     (yank)))
 
 (defun clipboard-kill-ring-save (beg end &optional region)
@@ -543,7 +541,7 @@
 If the optional argument REGION is non-nil, the function ignores
 BEG and END, and saves the current region instead."
   (interactive "r\np")
-  (let ((gui-select-enable-clipboard t))
+  (let ((select-enable-clipboard t))
     (kill-ring-save beg end region)))
 
 (defun clipboard-kill-region (beg end &optional region)
@@ -551,7 +549,7 @@ BEG and END, and saves the current region instead."
 If the optional argument REGION is non-nil, the function ignores
 BEG and END, and kills the current region instead."
   (interactive "r\np")
-  (let ((gui-select-enable-clipboard t))
+  (let ((select-enable-clipboard t))
     (kill-region beg end region)))
 
 (defun menu-bar-enable-clipboard ()

lisp/term/pc-win.el

@@ -263,7 +263,7 @@ Consult the selection.  Treat empty strings as if they were unset."
       (if (w16-selection-owner-p selection)
           t)
     ;; FIXME: Other systems don't obey
-    ;; gui-select-enable-clipboard here.
+    ;; select-enable-clipboard here.
     (with-demoted-errors "w16-set-clipboard-data: %S"
       (w16-set-clipboard-data value))
     value))