[cs615asa] flag recaptures

[Jan Schaumann]

The flag has been captured by several teams now, and there's a lot of
competition going on, trying to defend against a user with the same
capabilities.

I've removed access for the teams that I had marked as having possessed
the flag and reset certain credentials.

The following teams may stand down their efforts to retake the flag:
- Alien
- AlphaGo
- Pcshell
- Soga

The other teams are still in the race until I've seen them owning the
flag...