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I took the risk of writing some decorators (as it was the closest I could find to build helpers). I wasn't sure about how elegant it would be to use `t('whatever')` inside a decorator… just in case: sorry about that hehe…

I might have misunderstood a bit of the locale `.yml` organization, sorry about that too – I'm trying, but struggling when I feel that something could go in two or more different places.

Finally, there are also some TODOs that require a bit of back-end programming, if I have time I give them a try tomorrow.