Update PopulateVisit function to get only the new visits from Jamespot. In case the parameter "parrent_visit" is passed when creating a book, we copy all the slide corresponding to the visit being copied. Refactor PopulateVisite to PopulateVisit.

#!/usr/bin/env python
import os
import sys

if __name__ == "__main__":
    os.environ.setdefault("DJANGO_SETTINGS_MODULE", "settings")

    from django.core.management import execute_from_command_line

    execute_from_command_line(sys.argv)