Move nil-or-list-of-strings-p to a separate package

lisp/utils.el

@@ -0,0 +1,14 @@
+;;; utils --- Summary
+
+;;; Commentary:
+
+;;; Code:
+
+(defun nil-or-list-of-strings-p (var)
+  "Return t if VAR is either nil or a list holding only strings."
+  (or (null var)
+      (not (null (delq nil
+            (mapcar (lambda (x) (and (stringp x) x)) var))))))
+
+(provide 'utils)
+;;; utils.el ends here