interpreted dates basic model

arkindex/documents/admin.py

arkindex/documents/date_parser.py

arkindex/documents/management/commands/parse_dates.py

arkindex/documents/migrations/0002_interpreteddate.py

arkindex/documents/models.py

arkindex/documents/serializers/elements.py

arkindex/documents/tei.py

arkindex/documents/tests/commands/test_parse_dates.py

arkindex/documents/tests/tei_samples/update_after.xml

arkindex/documents/tests/tei_samples/update_before.xml

arkindex/documents/tests/test_act.py

arkindex/documents/tests/test_date_parser.py

arkindex/documents/tests/test_interpreted_date.py

arkindex/documents/tests/test_tei.py