Use user-error where error is inappropriate

* help-mode.el (help-go-back, help-go-forward, help-follow):
* simple.el (yank-pop, pop-to-mark-command, exchange-point-and-mark):
* winner.el (winner-redo):
* windmove.el (windmove-do-window-select):
* register.el (jump-to-register, increment-register, insert-register)
(append-to-register, prepend-to-register):
* files.el (find-alternate-file, abort-if-file-too-large, write-file)
(set-visited-file-name):
* emacs-lisp/lisp.el (kill-backward-up-list):
Use user-error instead of error. (Bug#14480)

lisp/emacs-lisp/lisp.el

@@ -263,7 +263,7 @@ This command assumes point is not in a string or comment."
           (backward-up-list arg)
           (kill-sexp)
           (insert current-sexp))
-      (error "Not at a sexp"))))
+      (user-error "Not at a sexp"))))
 
 (defvar beginning-of-defun-function nil
   "If non-nil, function for `beginning-of-defun-raw' to call.