tasks #6949 - Token generation

 * Check if option is activated
 * If option is activated, one mail is sent per recipient with new headers
 * Else, we keep the same behaviour as before

Change-Id: I225d7114d170fe96dd4345d09203b7bca50191c1
Merge commit 'refs/changes/40/2540/7' of ssh://gerrit.tuleap.net:29418/tuleap into stable

* ssh://gerrit.tuleap.net:29418/tuleap:
  tasks #6949 - Token generation
This is Tuleap 7.1.99.7

Change-Id: I9053c4ee72d0305e8cfa9b455e89e5877b965d28