Move Diffusion browse rendering to DocumentEngine, breaking almost all features

Summary:
Ref T13105. This breaks about 9,000 features but moves Diffusion to DocumentEngine for rendering. See T13105 for a more complete list of all the broken stuff.

But you can't bake a software without breaking all the features every time you make a change, right?

Test Plan: Viewed various files in Diffusion, used DocumentEngine features like highlighting and rendering engine selection.

Reviewers: mydeveloperday

Reviewed By: mydeveloperday

Subscribers: mydeveloperday

Maniphest Tasks: T13105

Differential Revision: https://secure.phabricator.com/D19302

src/applications/diffusion/application/PhabricatorDiffusionApplication.php

@@ -53,6 +53,8 @@ final class PhabricatorDiffusionApplication extends PhabricatorApplication {
         'history/(?P<dblob>.*)' => 'DiffusionHistoryController',
         'graph/(?P<dblob>.*)' => 'DiffusionGraphController',
         'browse/(?P<dblob>.*)' => 'DiffusionBrowseController',
+        'document/(?P<dblob>.*)'
+          => 'DiffusionDocumentController',
         'lastmodified/(?P<dblob>.*)' => 'DiffusionLastModifiedController',
         'diff/' => 'DiffusionDiffController',
         'tags/(?P<dblob>.*)' => 'DiffusionTagListController',