remove string-is-nil-or-empty? in utils and export it in validation.

This is a port I've been meaning to do for a while now; I just haven't got
around to it until now. This commit doesn't refactor the code in web.lisp to
call the ported code from validation -- it's just the first step in the port.

src/utils.lisp

@@ -56,18 +56,6 @@ allows each 'keyword' to have (white-)spaces."
 		   (read-from-string key))
 	:collect value))
 
-;; PORT CODE TO NO LONGER CALL THIS VERSION OF THE FUNCTION (MOVED TO VALIDATION PACKAGE).
-(defun string-is-nil-or-empty? (string-to-test)
-  "Tests to see if `STRING-TO-TEST' is empty of just whitespace.
-This is essentially the 'IsNullOrWhiteSpace' function I use in C#. It
-expands the 'empty string' check to include a check to see if there is
-string with just a '(white) space' in it."
-  (if (or (string= string-to-test " ")
-	  (zerop (length string-to-test))
-	  (null  string-to-test))
-      t
-      nil))
-
 (defun separate-files-in-web-request (request &optional request-value)
   "Creates a new list of 'upload' files from a web `REQUEST'.
 You will mostly use this for processing a multi-file upload (HTML)

src/validation.lisp

@@ -4,7 +4,8 @@
 	#:app-constants)
   (:export  #:has-static-assets-extention?
 	    #:is-valid-favicon-type?
-	    #:favicon-need-resizing?)
+	    #:favicon-need-resizing?
+            #:string-is-nil-or-empty?)
   (:documentation "Package for validating 'stuff'."))
 (in-package #:validation)
 
@@ -29,7 +30,6 @@ Valid file types are 'ico', 'gif' and 'png'."
 	 filename)
 	 (t nil)))
 
-;; TODO: PORT CODE TO CALL THIS VERSION OF STRING-IS-NIL-OR-EMPTY?
 (defun string-is-nil-or-empty? (string-to-test)
   "Tests to see if `STRING-TO-TEST' is empty of just whitespace.
 This is essentially the 'IsNullOrWhiteSpace' function I use in C#. It