Use Doxygen on last years code

[mikebowyer]

purpose: to decode last years code.

Install Doxtgen from the website, and:

• check box for "recursive", so that it digs into sub-folders.
• a check box somewhere to scan and analyze all files, not just the ones that are Doxygen formatted.
• Under graphics and creating charts, selecting Graphviz, and check the last two boxes to create call- and call-by- graphs.