After considerable discussion and experimentation, Erik and I have just completed a major simplification of the way server sources are managed on github. At this point, all the server sources are contained in two github repositories, powertac-core and powertac-server. The other 20 repositories (accounting, auctioneer, etc.) are now collapsed into these two repositories. So at this point, if you do a pull on server-interface, for example, you will get an empty directory.
This change should not affect you at all unless you are working with server sources. On the other hand, if you ARE working with server sources, you can no longer easily download or fork code for a single module; instead you will have to pull down all of powertac-server.
If you have been using STS or a similar tool to work with server sources, it will almost certainly be necessary at this point to delete all the server modules from your IDE and re-import them. I just finished doing that in my environment, and everything seems to be working correctly.
Thanks to Erik for researching and implementing this change. My role was mostly to finalize the change and make sure it all works afterward.
As always, if you have questions or encounter problems that you think might be associated with this change, please don't hesitate to ask.