Modular post-processing

Currently the post-processing needs to be run explicitly by the user and is very exact about the expected format. And the generated data/format are very rigid. This is somewhat related to #2 in the sense that I can imagine the profiler having a .add_postprocessor() method using which a series of data post-processors could be added. But I wonder how well this would work with the final data format. Do the post-processors define the format, is there a single format or should there also be a way to configure the final format?