Add acceptedStudentsCSVExport function to stats.py script. This funtion is used to generate CSV with all accepted students. It still needs some work and I left TODOs there. I also added helper function for saving data to CSV, which can be reused for other kinds of reports.

Benjamin Niemann <pink at odahoda dot de>: Main developer of Python target.
Clinton Roy <clinton.roy at gmail dot com>: AST templates and runtime.