[dataimport] Simple CSV import

Start of data import. This uses csv.DictReader to import csv files and return a dict with columns and rows keys. Includes a simple test.

Future enhancements should include:
    - detect csv delims and quote char
    - better file handling (use with statement, open read-only, take a string as well as a file)
    - clean up the csv during import (strip spaces)
    - more unit tests (more complex CSV files, check values in rows, error handling)