Phriction - kill tabs

Summary:
...except that pesky help tab which remains.

Pertinent bits here...
- move "History" into button "View History" that is grey and next to "Edit Page"
- for history page, add breadcrumb similar to the one on "diff" page.  This
unifies the experiencing on history <=> diffs as well as gives the user a link
back to the document, which was a tab on the History page before this diff.

Thoughts for next time...
- I'd like to further unify the breadcrumbs between "View" and "History / Diff".
- The "Document Index" is pretty sweet and feels a bit buried.  I wonder if
unifying breadcrumbs is the key here?

Test Plan: clicked around phriction.   viewed a document, viewed its history.
verified links in breadcrumbs were correct

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, epriestley

Maniphest Tasks: T631

Differential Revision: 1221

src/applications/phriction/controller/diff/PhrictionDiffController.php

@@ -195,10 +195,7 @@ class PhrictionDiffController
       ),
       array(
         'title'     => 'Document History',
-        'history'   => PhrictionDocument::getSlugURI($slug, 'history'),
-        'document'  => PhrictionDocument::getSlugURI($slug),
       ));
-
   }
 
   private function renderRevertButton(