Fixes performance issues of C++ one with Windows MSVC debug builds...
Merely a translation from msgfmt.cc code by @sergey, using BLI libs intead of C++'s stdlib.
Reviewers: sergey, campbellbarton, LazyDodo
Subscribers: sergey
Differential Revision: https://developer.blender.org/D2605
- Add blentranslation `BLT_*` module.
- moved & split `BLF_translation.h` into (`BLT_translation.h`, `BLT_lang.h`).
- moved `BLF_*_unifont` functions from `blf_translation.c` to new source file `blf_font_i18n.c`.