Replace legacy Differential queries for "open" revisions with a modern mechanism

Summary: Ref T2543. Several queries want only open revisions. Provide a tailored, non-legacy way to issue that query.

Test Plan: Viewed some of these callsites (e.g., "Similar open revisions affecting these files"), saw only open revisions.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T2543

Differential Revision: https://secure.phabricator.com/D18395

src/applications/diffusion/controller/DiffusionBrowseController.php

@@ -1758,7 +1758,7 @@ final class DiffusionBrowseController extends DiffusionController {
     $revisions = id(new DifferentialRevisionQuery())
       ->setViewer($viewer)
       ->withPath($repository->getID(), $path_id)
-      ->withStatus(DifferentialLegacyQuery::STATUS_OPEN)
+      ->withIsOpen(true)
       ->withUpdatedEpochBetween($recent, null)
       ->setOrder(DifferentialRevisionQuery::ORDER_MODIFIED)
       ->setLimit(10)