[ER] Show Future Events In Timeline

[cboos@…]

The timeline should be able to display future events as well as past events, therefore providing a time window around a given present time.

Of course, if the present time is really the present, there would be few future events to show:

• the upcoming Milestones
• a compact representation of the highest and high priority Tickets, maybe simply as a list like that:
  • High Priority Tickets: #9990, #9991, #9992, #9993
  • Highest Priority Tickets: #9994, #9995

But the present could also be set to an arbitrary date. The Timeline view would be very usefull to show what happened that date. In such case, it would be convenient to see what happenened just before and just after that date.

In particular, one could link the changeset timestamps to the Timeline with the present set to the value of that timestamp. In the end any timestamp displayed in Trac could actually be such a link.