update versions
add helper method for converting date formats
install gem to handle i18n
localize date formats and keep tests international running
Merge pull request #25 from leifg/master

generic pull request
remove debug output
add tests for the on member operations (also to increase test coverage)
change locale correct to english
Merge pull request #26 from leifg/localize_date

still looks the same, but if german locale is used, date format is dd.mm.yyyy