Allow currencies with exactly 8 decimal places (Bitcoin, Litecoin).

Hello,

I am using the MoneyDataExtension.csv file to add support for Bitcoin and Litecoin to my application. These currencies are usable down to 8 decimal places.

DefaultCurrencyUnitDataProvider currently only accepts "-1|1|2|3" when defining a currency's scale in the CSV file.

This patch alters the regular expression to allow it to accept 8 as well.

Alternatively, you could do something like -1|[1-8].