move xrd and hostmeta out of the OStatus plugin and into core

add event for setting up hostmeta, and use them in the OStatus plugin

plugins/OStatus/OStatusPlugin.php

@@ -50,8 +50,6 @@ class OStatusPlugin extends Plugin
     function onRouterInitialized($m)
     {
         // Discovery actions
-        $m->connect('.well-known/host-meta',
-                    array('action' => 'hostmeta'));
         $m->connect('main/xrd',
                     array('action' => 'userxrd'));
         $m->connect('main/ownerxrd',
@@ -1012,4 +1010,12 @@ class OStatusPlugin extends Plugin
 
         return true;
     }
+
+    function onStartHostMetaLinks(&$links) {
+        $url = common_local_url('userxrd');
+        $url.= '?uri={uri}';
+        $links[] = array('rel' => Discovery::LRDD_REL,
+                              'template' => $url,
+                              'title' => array('Resource Descriptor'));
+    }
 }