Front-end localization

[KEMiCZA]

Add localization so we can support multiple language's.

[fzxa]

@KEMiCZA Thank you for your suggestion, we will add it to the development plan.

[KEMiCZA]

@fzxa the code I published is not yet 100% right, we'll need to spend some more time to get this right. I'm not sure if the vuejs-localization library is the correct one to use.