#489 CDB file format WIKI page corrupt

[RvS]

I noticed that the description of the CDB file format in the WIKI is corrupted.
I made a new version that looks much better. During updating I also noticed that the description was not in line with the actual code, so I corrected that as well. As I do not have access to the WIKI I submit it via this patch.
Please check whether it now correctly describes the CDB-file format.