Convert inline profile image transforms to new transformations

Summary:
Ref T7707. Fixes T7879. Fixes T4406. When creating profile images:

  - Use the new transforms;
  - mark them as "profile" images so they're forced to the most-open policies.

Test Plan:
  - Set restrictive default file policies.
  - Changed profile picture, project pictures, etc. Verified they were visible to logged-out users.
  - Registered via OAuth.
  - Updated a Conpherence thread image.
  - Browsed around looking for profile images, fixed sizing on everything I could find.

Reviewers: chad, btrahan

Reviewed By: btrahan

Subscribers: epriestley

Maniphest Tasks: T7879, T7707, T4406

Differential Revision: https://secure.phabricator.com/D12821

src/applications/auth/controller/PhabricatorAuthRegisterController.php

@@ -604,17 +604,9 @@ final class PhabricatorAuthRegisterController
       return null;
     }
 
-    try {
-      $xformer = new PhabricatorImageTransformer();
-      return $xformer->executeProfileTransform(
-        $file,
-        $width = 50,
-        $min_height = 50,
-        $max_height = 50);
-    } catch (Exception $ex) {
-      phlog($ex);
-      return null;
-    }
+    $xform = PhabricatorFileTransform::getTransformByKey(
+      PhabricatorFileThumbnailTransform::TRANSFORM_PROFILE);
+    return $xform->executeTransform($file);
   }
 
   protected function renderError($message) {