Yes, Javadocs have always been part of the software. They are found in the qcchart2djava.jar file, found in the quinn-curtis\java\lib folder. That is why the jar files in that folder are so large, compared to the ones with the same name in the quinn-curtis\java\redistributables folder, which do not have internal Javadoc files.
Just search on Javadoc in the manual for instructions. It starts around the fourth page of Chapter 24 - Compiling and Running the Example Programs, in the QCChart2D manual.