Looks for settings under DJANGO_HISTORY_SETTINGS, supporting dot notation for nested lookups,
    eg. get_setting('EXCLUDE_CHANGES.fields')

def get_setting(name):
    """ Looks for settings under DJANGO_HISTORY_SETTINGS, supporting dot notation for nested lookups,
    eg. get_setting('EXCLUDE_CHANGES.fields') """
    dh = getattr(settings, 'DJANGO_HISTORY_SETTINGS', {})
    result = None
    for k in name.split('.'):
        if dh is None:
            continue
        result = dh.get(k, None)
        dh = result
    return result