Add ability to download batch row data as CSV.

tailbone/templates/batch/view.mako

@@ -13,6 +13,13 @@
   </script>
 </%def>
 
+<%def name="context_menu_items()">
+  ${parent.context_menu_items()}
+  % if request.has_perm('{0}.csv'.format(permission_prefix)):
+      <li>${h.link_to("Download this {0} as CSV".format(batch_display), url('{0}.csv'.format(route_prefix), uuid=batch.uuid))}</li>
+  % endif
+</%def>
+
 <%def name="buttons()">
     <div class="buttons">
       % if not form.readonly and batch.refreshable: