I18n updates



See merge request !4

Translation toolkit for ToME4

Prototype of builtin translation toolkit for ToME4.
It is designed to replace the old i18n_tools native lua script interface.

How to use:
* This addon will add "Translation Tool" menu in debug menu, in this menu
  * __Change working locale__ will change your working locale
  * __Create translation addon__ is used to create a template addon to test your translation project.
  * __Extract text index__ must be executed before the two following operation, it will extract game text in your game file. You should rerun this operation whenever game code (excluding locale) changes.
  * __Rearrange translation files__ will help you arrange translation file in your translation working folder, it will create empty translation files, as well as arrange, deduplicate and detect conflict translations in your files.
  * __Check translation files__ just do the conflict detection work
  * __Release translation as addon__ can be used to copy your translation file to an addon.
* Working dir is `{engine.homepath}/user-i18n/`
* Additional file to help rearrange translation files
  * `_tdef_append.lua` is used to mark text that does not appear in game as _t string but should be translated.
     * For example, `northwest` is a combination of "north" and "west" in game, but it may appear as an independent word in your language.
     * Also, `magestaff` that does not appear as _t. It's the key for key-value staff flavor defination in game, and we may not want to change this for compatibility.
     * This is still subject to interface changes, currently, you can get a up-to-date `_tdef_append.lua` in https://pastebin.com/tJS5SCt6
 * `_t_append.lua` can be used to add translations into your project. It can be also used for migration from the old framework.
 * `_not_merged.lua` is, strings that don't appear in current game, being evicted and stored here.
Current work:
Documents (Important!)
More tests
Additional features on request

See merge request !3

chinese locale



See merge request !2

Merge branch 'otowakotori/tome-addon-dev-i18n'