'pseudo' locale files for testing/development + script to generate these files

Here I include a script that generates both client.pseudo.yml and server.pseudo.yml localization files from the current 'en' strings. Just run `./script/generate-pseudolocalization.rb` from the project root.

The pseudo locale is useful for development/testing/localization – you can see if there are any UTF8 problems, if there are any strings left directly in the code, where the strings get concatenated, etc.