Add support for "new-style grids" and "model master views".

Finally, an API that makes some sense...  We don't yet have feature parity
with the old-style grids and CRUD views, but this is already a significant
improvement to the design.  Still needs a lot of docs though...

tailbone/templates/settings/index.mako

@@ -1,12 +0,0 @@
-## -*- coding: utf-8 -*-
-<%inherit file="/grid.mako" />
-
-<%def name="title()">Settings</%def>
-
-<%def name="context_menu_items()">
-  % if request.has_perm('settings.create'):
-      <li>${h.link_to("Create a new Setting", url('settings.create'))}</li>
-  % endif
-</%def>
-
-${parent.body()}