I wanted to share this. The previous developers didn't use any source control, they simply did the same thing by renaming the old files and added new ones. The file names have been changed to protect the guilty:

This WTF is completely a human problem. Given a bad situation people (especially bad programmers) will find the ways to make it worse. The problem gets worse when dumb developers start using those old libraries! Now your messy directories have turned into software requirements! This may sound retarded but this has happened, and will happen!