Conpherence - refactor display classes a bit

Summary:
D12409 made me realize this was a bit janky. `PhabricatorTransactionView` was only being used by Conpherence, so move and rename that class to `ConpherenceTransactionView`. Also, rename the existing `ConpherenceTransactionView` to `ConpherenceTransactionRenderer`, moving the actual view bits into the new `ConpherenceTransactionView`. Resulting code is a bit cleaner IMO.

Diff 1 of 2 (second diff has to be written. =D). Diff 2 will take care of the CSS and possibly clean things up further.

Test Plan: played around in conpherence full and conpherence column and things looked nice

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin, epriestley

Differential Revision: https://secure.phabricator.com/D12410

src/applications/conpherence/controller/ConpherenceUpdateController.php

@@ -408,7 +408,7 @@ final class ConpherenceUpdateController
 
     $non_update = false;
     if ($need_transactions && $conpherence->getTransactions()) {
-      $data = ConpherenceTransactionView::renderTransactions(
+      $data = ConpherenceTransactionRenderer::renderTransactions(
         $user,
         $conpherence,
         !$this->getRequest()->getExists('minimal_display'));