Multi-language support (localization)

[brlima94]

Dear Intel team,

It's nice to see this project getting back to some traction, however I have a few concerns about all the issues which were closed without too much of a criteria.

When ACAT was first released, we built a few language packs to expand this great project's accessibility to a wide range of users from non-English speaking countries.
Unfortunately, our effort was lost with the many times this repo had its code entirely deleted and re-added in GitHub.

The latest source code only has EN support and part of the project (ConvAssist) is closed-source.
The latest mention of localization/translation I found was in the v1.50 release notes.

I believe this is still a required feature because:

1. This topic was raised in multiple issues over the years, e.g.:

• More Language Support? #7
• Localization. #11
• LOCALIZATION #29
• UI y Diccionario en Español #30
• No Support to PT-BR (Limitation) #45
• DUTCH Language Pack #64
• Beginning of a Dutch language pack, for someone else to improve on. #68

2. One user recently contacted me asking if we could update the language pack created for v0,98, which he was still using (you can check them here if you wish

So I would like to propose if we could give some priority to this topic.

I can open a few PRs with incremental work for each language, but before starting, I would like to request:

1. some commitment that this will not be another wasted effort (someone will review the PRs and provide feedback promptly, merging the code when it's all good)
2. that you do not delete and recreate the code in future releases. Instead, use git merges from your private repo to GitHub if needed. Feel free to ask when localization needs some adjustments, but do not delete everything without notice
3. for ConvAssist to be published or alternate instructions on how to build+debug the project locally
4. instructions on how to create new language packs, even better if I can reuse the n-gram DBs already built with Presage

If you don't mind, I want to start by adding a command-line switch to set the UI language. It was a huge pain point having to install multiple languages in Windows (or use a VM) just to run ACAT.

Please let me know your thoughts and if you can assist me with this - @saiprasadb01 , @michaelbeale-IL , @rdower or anyone else available.