#851 Prototype Tracker milestone tracking
We currently don't do anything special with milestones in the tracker, which creates some usability issues.
There should be a new admin page for editing milestones, and it should contain:
- Milestone name
- Milestone description (in markdown)
- and a "completed" boolean
We should display a section in the left bar of the tracker (like saved searches) showing all "active" (not completed) milestones. Each milestone link should reflect the number of items in that milestone (like saved searches) and the milestone page itself should show a description of the milestone at the top, followed immediately by a saved search for all tickets in that milestone.
I'm going to move https://sourceforge.net/p/allura/tickets/851/ out of this milestone, as the milestone changes in the new UI mockups are big enough that I think it's worth doing those on a second round through the tracker.