Update *both* uses of the URL to the zlib home page, and use the version

advertised as the canonical form.

Doc/lib/libzlib.tex

@@ -9,10 +9,10 @@
 For applications that require data compression, the functions in this
 module allow compression and decompression, using the zlib library.
 The zlib library has its own home page at
-\url{ftp://ftp.freesoftware.com/pub/infozip/zlib/zlib.html}.  Version
-1.1.3 is the most recent version as of September 2000; use a later
-version if one is available.  There are known incompatibilities
-between the Python module and earlier versions of the zlib library.
+\url{http://www.info-zip.org/pub/infozip/zlib/}.  Version 1.1.3 is the
+most recent version as of September 2000; use a later version if one
+is available.  There are known incompatibilities between the Python
+module and earlier versions of the zlib library.
 
 The available exception and functions in this module are:
 
@@ -149,6 +149,6 @@ action is to delete the object.
 
 \begin{seealso}
   \seemodule{gzip}{reading and writing \program{gzip}-format files}
-  \seetext{The zlib library home page is located at
-           \url{http://www.cdrom.com/pub/infozip/zlib/}.}
+  \seeurl{http://www.info-zip.org/pub/infozip/zlib/}{The
+          zlib library home page.}
 \end{seealso}