Fix links to Textile reference in the wake of _why's disappearance.

vendor/extensions/textile_filter/textile.html

@@ -1,4 +1,4 @@
-<p>Many people prefer <a href="http://textism.com/tools/textile/" target="_blank">Textile</a>
+<p>Many people prefer <a href="http://en.wikipedia.org/wiki/Textile_(markup_language)" target="_blank">Textile</a>
   over standard HTML because it is less verbose. Textile is very similar
   to plain text, but there are a few additional enhancements to make it
   suitable for hypertext documents.</p>
@@ -111,5 +111,5 @@ <h4>Heading 4</h4>
 
 <p>Advanced users may want to play around with the official
   <a href="http://textism.com/tools/textile/" target="_blank">Textile Dingus</a> or review 
-  <a href="http://hobix.com/textile/" target="_blank">Why the Lucky Stiff&#8217;s Textile
+  the <a href="http://redcloth.org/textile/" target="_blank">RedCloth Textile
   Reference</a>.</p>