Substantially support character encodings and "Highlight As" in changesets

Summary: Ref T5179. Ref T4045. Ref T832. We can now write non-utf8 hunks into the database, so try to do more reasonable things with them in the UI.

Test Plan: (See screenshots...)

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: epriestley

Maniphest Tasks: T832, T4045, T5179

Differential Revision: https://secure.phabricator.com/D9294

src/applications/differential/controller/DifferentialChangesetViewController.php

@@ -155,6 +155,8 @@ final class DifferentialChangesetViewController extends DifferentialController {
     $parser->setRightSideCommentMapping($right_source, $right_new);
     $parser->setLeftSideCommentMapping($left_source, $left_new);
     $parser->setWhitespaceMode($request->getStr('whitespace'));
+    $parser->setCharacterEncoding($request->getStr('encoding'));
+    $parser->setHighlightAs($request->getStr('highlight'));
 
     if ($request->getStr('renderer') == '1up') {
       $parser->setRenderer(new DifferentialChangesetOneUpRenderer());