auto-import of subject data

It should be implemented in similar way to redcap connector (django cron job):

• Create a cron job that will automatically add subjects from external file (assume csv). The data could contain subject information and study_subject information.

• Subject data can be added or updated (it will be delta).

• Data provenance should be kept for such updates.

• Summary email should be send after automatic import, without patient data pure statistics.

• Automatic export of excluded subjects into the file