modularize log file format
In the future we need to track more high level library and data model information in Darshan. Right now, however, the log file format has to change every time we modify any counters and it gets larger with each interface we instrument.
It would be nice if the counters in darshan weren't just an array of integers, but instead had a concept of dividing the information into opaque sections for each type of instrumentation. That would allow us to experiment with new instrumentation (and parsers for that portion of the instrumentation) without breaking the entire file format. Old parsers could ignore any optional sections of the log file that it doesn't know how to parse.