Money referentials

src/sakia/app.py

src/sakia/money/base_referential.py

src/sakia/money/dividend_per_day.py

src/sakia/money/quant_zerosum.py

src/sakia/money/quantitative.py

src/sakia/money/relative.py

src/sakia/money/relative_to_past.py

src/sakia/money/relative_zerosum.py

src/sakia/money/udd_to_past.py