Ref T12074.
- project.search now returns milestones by default.
- A new constraint, isMilestone, allows filtering to milestones, non-milestones, or both (API and web UI).
- project.search now returns a milestone number for milestones, or null for non-milestones.
NOTE: Existing custom saved queries in projects which previously did not return milestones now will. I expect this to have little-to-no impact on users, and these queries are easy to correct, but I'll note this in changelogs.