OStatus feedsub fixlets:

- actually udpate feedsub.last_update when we get a new PuSH update in
- move incoming PuSH processing to a queue handler to minimize time spent before POST return, as recommended by PuSH spec. When queues are disabled this'll still be handled immediately.

plugins/OStatus/classes/FeedSub.php

@@ -372,6 +372,12 @@ class FeedSub extends Memcached_DataObject
      * feed (as a DOMDocument) will be passed to the StartFeedSubHandleFeed
      * and EndFeedSubHandleFeed events for processing.
      *
+     * Not guaranteed to be running in an immediate POST context; may be run
+     * from a queue handler.
+     *
+     * Side effects: the feedsub record's lastupdate field will be updated
+     * to the current time (not published time) if we got a legit update.
+     *
      * @param string $post source of Atom or RSS feed
      * @param string $hmac X-Hub-Signature header, if present
      */
@@ -402,6 +408,10 @@ class FeedSub extends Memcached_DataObject
             return;
         }
 
+        $orig = clone($this);
+        $this->last_update = common_sql_now();
+        $this->update($orig);
+
         Event::handle('StartFeedSubReceive', array($this, $feed));
         Event::handle('EndFeedSubReceive', array($this, $feed));
     }