Fix #2706 - Always respond with 200 to PuSH payloads (#2733)

Fix #2196 - Respond with 201 when Salmon accepted, 400 when unverified
Fix #2629 - Correctly handle confirm_domain? for local accounts
Unify rules for extracting author acct from XML, prefer <email>, fall back
to <name> + <uri> (see also #2017, #2172)

app/controllers/api/subscriptions_controller.rb

@@ -19,10 +19,9 @@ class Api::SubscriptionsController < ApiController
 
     if subscription.verify(body, request.headers['HTTP_X_HUB_SIGNATURE'])
       ProcessingWorker.perform_async(@account.id, body.force_encoding('UTF-8'))
-      head 201
-    else
-      head 202
     end
+
+    head 200
   end
 
   private