Allow for other currency symbols while calculating money_score

This patch still gives columns a money score as long as they fit \d*[,\.]\d\d$ regex pattern. This makes sure that other currency symbols than the $ get accepted.

The patch is build on pull request #23 since it uses the same test case.

Ideally one would specifically test for pound and euro symbols, but I could not get a regex for that to work. Probably since utf-8 support of (older versions) of ruby is quite poor. Also that would mean we would have to test separately for each type of currency symbol. This should help with any type of currency symbol.