A very important feature of issue tracking system is to keep track of issues history.

For the moment XooSent is very poor in this area, you can only add comments, but when you have no trace of the modifications done to the issue itself (status change, ...).

XooSent model has already been designed for this, since comments are indeed only a special kind of issue event in the history. So what need to be done is to add a new issue event subclass, and create new instances automatically when issue is edited.