Helpful regexp message

A user of mine complained that the joi output is not verbose enough. It didn't show the value that didn't match the regular expression. I added a few properties and added a new locale support. Right now I only added the value to the string object. While I added this I also added a new approach to encoding. Please treat this as an experimental pull request and a suggestion to discuss if the current way how the differentiation between language code and user messages work.