Rename util_show_error_page() to util_show_error_page_and_exit() and redirect() to util_redirect_and_exit()

so it is explicit that we exit in those functions that so we know it isn't necessary to put an exit after
we call them

include/util.php

@@ -2,7 +2,7 @@
 /**
  * display an error page
  */
-function util_show_error_page($text = null, $message = null)
+function util_show_error_page_and_exit($text = null, $message = null)
 {
     if (!$text) {
         $text = "You must be logged in to perform that operation.";
@@ -15,6 +15,15 @@ function util_show_error_page($text = null, $message = null)
     exit;
 }
 
+/**
+ * redirect to $url
+ */
+function util_redirect_and_exit($url)
+{
+    header("Location: ".$url); 
+    exit;
+}
+
 function makeSafe($var)
 {
 /* Disable addslashes() until we can use more finely grained filtering on user input */