Respect currency digit settings.

The supplemental currency data should be respected when
formatting currencies. In particular this means some
currencies should always have a certain number of digits
after the decimal point.

http://www.unicode.org/reports/tr35/tr35-numbers.html#Supplemental_Currency_Data

Conflicts:
	scripts/import_cldr.py
	tests/test_numbers.py

Conflicts:
	scripts/import_cldr.py
	tests/test_numbers.py