CSV for manual payments
To ease the integration with the billingsystem we should
provide export of all manual payments as CSV.

We have use the CSV Shaper library, which provides a slick
Rails DSL for returning CSV files.
http://github.com/paulspringett/csv_shaper
Added city and organization as optional fields for manual payments
Merge pull request #33 from smidig/csv_manual_payments

Csv manual payments