Feature request: remember and reuse last translate direction

[QiangF]

When I am reading a paper, the translate direction doesn't change often. If the pair is not at the beginning of gts-translate-list, I have to go down and choose every time.

For example, in my current setting, gts-do-translate will always start with en->zh, if the language is Japanese, I need to press M-n twice. The next invocation of gts-do-translate on another Japanese text will repeat the above procedure. Why not remember the first choice?

 (setq gts-translate-list '(("en" "zh")
                            ("ru" "en")
                            ("ja" "en")
                            ("de" "en")
                            ("fr" "en")))

 (setq gts-default-translator
       (gts-translator
        :picker (gts-noprompt-picker)
        :engines (gts-google-rpc-engine)
        :render (gts-buffer-render)))

[QiangF]

I see there are variables like gts-picker-current-path and gts-picker-last-path, seems like the last path in my above use case is not saved.

[QiangF]

I feel the gts path stuff is too complicated, maybe make auto guess language optional, most user just need a few fixed translation directions.