Use PhrictionDocumentQuery to load documents

Summary: Ref T4029. We use a lot of very outdated content loading in Phriction, which blocks T4029.

Test Plan:
- Called phriction.info
- Called phriction.history
- Called phriction.edit
- Viewed document list.
- Deleted a document.
- Viewed history.
- Viewed a diff.
- Created a document.
- Edited a document.
- Moved a document.
- Tried to overwrite a document with "new".
- Tried to overwrite a document with "move".
- Viewed a moved document note.

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: shadowhand, epriestley

Maniphest Tasks: T4029

Differential Revision: https://secure.phabricator.com/D9194

src/applications/phriction/controller/PhrictionDiffController.php

@@ -13,16 +13,19 @@ final class PhrictionDiffController
   }
 
   public function processRequest() {
-
     $request = $this->getRequest();
     $user = $request->getUser();
 
-    $document = id(new PhrictionDocument())->load($this->id);
+    $document = id(new PhrictionDocumentQuery())
+      ->setViewer($user)
+      ->withIDs(array($this->id))
+      ->needContent(true)
+      ->executeOne();
     if (!$document) {
       return new Aphront404Response();
     }
 
-    $current = id(new PhrictionContent())->load($document->getContentID());
+    $current = $document->getContent();
 
     $l = $request->getInt('l');
     $r = $request->getInt('r');