Translations:How Fcitx works/27/en

There're times that fcitx ignored some kinds of backward compatibility (4.0 -> 4.1 skin change, 3.6 -> 4.0 data format and configuration layout change), but since 4.2 we finally reach a level that we don't have much limitation, and things are well organized, there is no more excuse can be taken for not keep the backward compatibility.