update some links to new locations

docs/refguide.xml

@@ -1575,7 +1575,7 @@ way.</para>
     enables version detection among other things.  A paper documenting
     the workings, usage, and customization of version detection is
     available at <ulink
-    url="http://nmap.org/vscan/" />.</para>
+    url="http://nmap.org/book/vscan.html" />.</para>
 
     <para>When Nmap receives responses from a service but cannot match
     them to its database, it prints out a special fingerprint and
@@ -1765,7 +1765,7 @@ way.</para>
 
     <para>A paper documenting the workings, usage, and customization
     of OS detection is available at <ulink
-    url="http://nmap.org/osdetect/" />.</para>
+    url="http://nmap.org/book/osdetect.html" />.</para>
 
     <para>OS detection is enabled and controlled with the following options:</para>
 
@@ -1852,7 +1852,7 @@ way.</para>
 	network handling with the versatility of the lightweight scripting language
 	<ulink url="http://lua.org">Lua</ulink>, thus providing innumerable
 	opportunities.  A more extensive documentation of the NSE (including its
-	API) can be found at: <ulink url="http://nmap.org/nse/"/>. The
+	API) can be found at: <ulink url="http://nmap.org/book/nse.html"/>. The
 	target of the NSE is to provide Nmap with a flexible infrastructure for
 	extending its capabilities and offering its users a simple way of creating
 	customized tests. Uses for the NSE include (but definitely are not limited
@@ -1925,7 +1925,7 @@ way.</para>
     you are not required to follow this for the moment, this may change in the
     future. Nmap will issue a warning if a file has any other extension.
     More extensive documentation on the NSE, including a description of its API
-    can be found at <ulink url="http://nmap.org/nse/" />.
+    can be found at <ulink url="http://nmap.org/book/nse.html" />.
     </para>
    
 	<variablelist>