Improve checkbox click handling support for grids

i.e. let custom use define click handlers

tailbone/templates/master/index.mako

@@ -253,7 +253,7 @@
 </%def>
 
 <%def name="page_content()">
-  <tailbone-grid
+  <tailbone-grid :csrftoken="csrftoken"
      % if master.deletable and request.has_perm('{}.delete'.format(permission_prefix)) and master.delete_confirm == 'simple':
      @deleteActionClicked="deleteObject"
      % endif