Better server test in redirect() of URL helper
"Location" header bugs are specific to IIS; previous test was matching
all HTTP servers under Windows.
This test isn't perfect yet ($_SERVER['SERVER_SOFTWARE'], which
corresponds to the "Server" header of HTTP response, might be missing),
but there is no perfect test.
"Refresh" method makes the window blank for quite a noticeable time,
so let's not affect other servers because of IIS.
diff --git a/user_guide_src/source/helpers/url_helper.rst b/user_guide_src/source/helpers/url_helper.rst
index 3054540..8de7817 100644
--- a/user_guide_src/source/helpers/url_helper.rst
+++ b/user_guide_src/source/helpers/url_helper.rst
@@ -303,7 +303,7 @@
The optional second parameter allows you to force a particular redirection
method. The available methods are "location" or "refresh", with location
-being faster but less reliable on Windows servers. The default is "auto",
+being faster but less reliable on IIS servers. The default is "auto",
which will attempt to intelligently choose the method based on the server
environment.