Add sidebar to compaction page

This ticket adds the sidebar to the Compaction page and refactors
the code a little to start explictly stating what resources and Views
in the documents addon are intended for sharing.

Closes COUCHDB-2404
This function looks exactly like the initialize function for `DocumentsRouteObject`. I think we should break all these sections into smaller functions in the DocumentsRouteObject. Then this RouteObject can inherit or Mixin those functions. So then the initialize function would look something like this:

    initialize: function () {
      this.createDesignDocCollection();
      this.setLeftheader();
      this.setSidebar();
     }

This would then make it that any changes or bug fixes we do should apply across modules. For example the lookahead tray bug fix would automatically be fixed in the compaction module as its using the same code to generate the sidebar.