Switch to side-by-side view

--- a/Allura/allura/controllers/repository.py
+++ b/Allura/allura/controllers/repository.py
@@ -28,6 +28,7 @@
 from allura.lib.widgets.repo import SCMMergeRequestDisposeWidget, SCMCommitBrowserWidget
 from allura import model as M
 from allura.lib.widgets import form_fields as ffw
+from allura.controllers.base import DispatchIndex
 
 from .base import BaseController
 
@@ -439,7 +440,7 @@
             count=count,
             **kw)
 
-class TreeBrowser(BaseController):
+class TreeBrowser(BaseController, DispatchIndex):
     tree_widget = SCMTreeWidget()
     FileBrowserClass=None