OpenRA/OpenRA — pull request #6706 by pchote (2014-10-07 09:28:17+00:00)
Title: Improve the mission menu

![fmv](https://cloud.githubusercontent.com/assets/167819/4540073/ec913894-4e03-11e4-86ca-03621eb1f990.png)

This implements the second phase of the mission menu plan:
* Support groups of related missions.
* Play briefing FMV before starting the mission.