editable description

[``* `#16988` editable description``](http://community.openproject.org/work_packages/16988)
I guess this applies a help link style. If so, please put this in a separate method and you may also put the ``class``, ``type``, and ``text`` attributes in a constant. ``class`` and ``type`` have quotation marks whereas ``text`` and ``click`` not. Is there something special?