Let mobile form declare if/how to auto-focus a field

and for mobile ordering, auto-focus the "units" field when editing a row

tailbone/templates/mobile/master/edit_row.mako

@@ -5,15 +5,7 @@
 
 <%def name="page_title()">${h.link_to(index_title, index_url)} &raquo; ${h.link_to(parent_title, parent_url)} &raquo; ${h.link_to(instance_title, instance_url)} &raquo; Edit</%def>
 
-## TODO: this should not be necessary, correct?
-## <%def name="buttons()">
-##   <br />
-##   ${h.submit('create', form.update_label)}
-##   ${h.link_to("Cancel", form.cancel_url, class_='ui-btn ui-corner-all')}
-## </%def>
-
 <div class="form-wrapper">
-##  ${form.render(buttons=capture(self.buttons))|n}
   ${form.render()|n}
 </div><!-- form-wrapper -->