Change STLport links to point to the sourceforge page.

[SVN r37108]

config.htm

@@ -34,7 +34,7 @@
          should be able to use boost "as is". Since the compiler is configured 
          separately from the standard library, the default configuration should work 
          even if you replace the compiler's standard library with a third-party standard 
-         library (like <a href="http://www.stlport.org">STLport</a>).
+         library (like <a href="http://stlport.sourceforge.net">STLport</a>).
       </p>
       <p>Using boost "as is" without trying to reconfigure is the recommended method for 
          using boost. You can, however, run the configure script if you want to, and