License information for data files

[langner]

This is both a current issue and copied from Sourceforge (#21). Namely, it would be prudent to provide some kind of license information concerning the data files we have here. We have had some discussion on the mailing list, but there doesn't seem to be one correct way to proceed.

On the one hand, the raw data -- which is what we are interested in -- is not subject to copyright. On the other hand, there are clear copyright statements in logfiles (referring to the software, not data), and any license cannot cover those portions of the logfiles.