only localize by language, dismiss the country code
fix `{n} Members` message

For numbers greater than 999 the `.replace(str(community.nmembers), ...)` hack would not have worked.
bring back JS tests

They were turned off to ease development.
simplify messages
fix credit card page
small shortcut
minor simplifications
Merge pull request #2639 from gittip/fix-i18n

Fix i18n