committed in rev6319:20e77c3ce6f6.

Also you might want to add the ability to stay in
add new keyword mode. The code to do this in the classic tracker is:

     <input type="checkbox" id="continue_new_keyword"
            name="__redirect_to"
            tal:attributes="value
                            
string:${request/base}${request/env/PATH_INFO}?@template=item;
                            checked python:True" />
     <label for="continue_new_keyword" i18n:translate="">Continue adding 
keywords.</label>