Mark "low importance" and "owned" changes in the filetree

Summary: Ref T13516. Mark low-importance changes (generated code, deleted files) and owned-with-authority changes in the filetree.

Test Plan: {F7375327}

Maniphest Tasks: T13516

Differential Revision: https://secure.phabricator.com/D21157

webroot/rsrc/js/application/diff/DiffTreeView.js

@@ -106,7 +106,8 @@ JX.install('DiffTreeView', {
             .setPath(tree.parts);
 
           path.getIcon()
-            .setIcon('fa-folder-open-o');
+            .setIcon('fa-folder-open-o')
+            .setColor('grey');
 
           tree.pathObject = path;
         }