Fix the URL for the regex-to-re HOWTO.

Doc/lib/libregex.tex

@@ -15,7 +15,7 @@ converted.  The standard library module
 \code{reconvert}\refstmodindex{reconvert} helps in converting
 \code{regex} style regular expressions to \code{re}\refstmodindex{re}
 style regular expressions.  (For more conversion help, see the URL
-\url{http://starship.skyport.net/crew/amk/regex/regex-to-re.html}.)
+\url{http://starship.skyport.net/crew/amk/howto/regex-to-re.html}.)
 
 By default the patterns are Emacs-style regular expressions
 (with one exception).  There is

Doc/lib/libregsub.tex

@@ -16,7 +16,7 @@ Existing code should be converted.  The standard library module
 \module{reconvert} helps in converting \code{regex} style regular
 expressions to \module{re} style regular expressions.  (For more
 conversion help, see the URL
-\url{http://starship.skyport.net/crew/amk/regex/regex-to-re.html}.)
+\url{http://starship.skyport.net/crew/amk/howto/regex-to-re.html}.)
 
 \setindexsubitem{(in module regsub)}
 

Doc/libregex.tex

@@ -15,7 +15,7 @@ converted.  The standard library module
 \code{reconvert}\refstmodindex{reconvert} helps in converting
 \code{regex} style regular expressions to \code{re}\refstmodindex{re}
 style regular expressions.  (For more conversion help, see the URL
-\url{http://starship.skyport.net/crew/amk/regex/regex-to-re.html}.)
+\url{http://starship.skyport.net/crew/amk/howto/regex-to-re.html}.)
 
 By default the patterns are Emacs-style regular expressions
 (with one exception).  There is

Doc/libregsub.tex

@@ -16,7 +16,7 @@ Existing code should be converted.  The standard library module
 \module{reconvert} helps in converting \code{regex} style regular
 expressions to \module{re} style regular expressions.  (For more
 conversion help, see the URL
-\url{http://starship.skyport.net/crew/amk/regex/regex-to-re.html}.)
+\url{http://starship.skyport.net/crew/amk/howto/regex-to-re.html}.)
 
 \setindexsubitem{(in module regsub)}