Provide an "event" page for push logs, which shows details on all events in a given push

Summary:
Ref T4677. This shows a more detailed view of an entire "git push", "hg push", or "svn commit".

This is mostly to give push summary emails a reasonable, stable URI to link to for T4677.

Test Plan:
  - Pushed into SVN, Git and Mercurial.
  - Viewed partial and imported event records.

{F134864}

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: epriestley

Maniphest Tasks: T4677

Differential Revision: https://secure.phabricator.com/D8616

src/applications/diffusion/application/PhabricatorApplicationDiffusion.php

@@ -47,9 +47,10 @@ final class PhabricatorApplicationDiffusion extends PhabricatorApplication {
         'new/' => 'DiffusionRepositoryNewController',
         '(?P<edit>create)/' => 'DiffusionRepositoryCreateController',
         '(?P<edit>import)/' => 'DiffusionRepositoryCreateController',
-        'pushlog/(?:query/(?P<queryKey>[^/]+)/)?'
-          => 'DiffusionPushLogListController',
-
+        'pushlog/' => array(
+          '(?:query/(?P<queryKey>[^/]+)/)?' => 'DiffusionPushLogListController',
+          'view/(?P<id>\d+)/' => 'DiffusionPushEventViewController',
+        ),
         '(?P<callsign>[A-Z]+)/' => array(
           '' => 'DiffusionRepositoryController',