Minor bug fix to Barbarians for DOS

I discovered a couple of minor issues with the release version of Barbarians for DOS, so I've uploaded a new copy of the ZIP file over the old. If you're happily playing the game and haven't noticed these issues, you don't really need to update, as the release version works and plays fine. But the bugs I noticed were:

1. When arming citizens, the empire-wide population figure (in the left panel) wasn't updated on the screen. It was updated internally though, so game play wasn't affected, and it would be updated on the screen at the end of your turn.
2. If the barbarians advanced without attacking any of your armies or cities, the marching sound effect would play before the screen was updated.

Both of these issues have been fixed, and at the same time I noticed I hadn't added a licence or readme file to the original zip, so I've fixed that too.