Scan for languages

[akirashirosawa]

Summary

SUMMARY: None

Purpose of change

I have to constantly switch languages for testing, and it’s very annoying to scroll through them all. I thought it would be nice if displayed only languages ​​for which there is a translation. Then I found this in the code: TODO: scan for languages like we do for tilesets. So, let's do it!

Describe the solution

Scan for languages like we do for tilesets. Added lang info to the PATH_INFO added actual_lang_options near lang_options. Completely replace lang_options by actual_lang_options. Added probably forgotten brake in for cycle.

Describe alternatives you've considered

Reuse lang info, that I added to PATH_INFO on the translations.cpp:

// Step 2. Bind to gettext domain.
    std::string locale_dir;
#if defined(__ANDROID__)
    // HACK: Since we're using libintl-lite instead of libintl on Android, we hack the locale_dir to point directly to the .mo file.
    // This is because of our hacky libintl-lite bindtextdomain() implementation.
    auto env = getenv( "LANGUAGE" );
    locale_dir = std::string( PATH_INFO::base_path() + "lang/mo/" + ( env ? env : "none" ) +
                              "/LC_MESSAGES/cataclysm-dda.mo" );
#elif (defined(__linux__) || (defined(MACOSX) && !defined(TILES)))
    if( !PATH_INFO::base_path().empty() ) {
        locale_dir = PATH_INFO::base_path() + "share/locale";
    } else {
        locale_dir = "lang/mo";
    }
#else
    locale_dir = "lang/mo";
#endif

But, there are some scary __ANDROID__ HACKs and some strange defined(__linux__) || (defined(MACOSX) && !defined(TILES)) instead of #if defined(DATA_DIR_PREFIX) that in path_info.cpp.

Testing

Language option displays only available languages (for which there is a translation in .mo files).

Additional context

I am using lambda expressions in C++ for the first time, it would be nice if more experienced contributor checked the code.

[RedShakespeare]

Cannot work well with Android OS...Hope for some fixing.