Support Chinese (Traditional: zh-Hant and Simplified: zh-hans), respectively

In practice:
zh-CN and zh-SG/zh-MY are subsets of zh-Hans
zh-TW and zh-HK/zh-MO are subset of zh-Hant

So GTK should consider supporting zh-Hans / zh-Hant

__KDE support__
KDE supported zh-Hans/zh-Hant many years, pls see commands:

sudo apt-get install language-pack-kde-zh-hans-base
sudo apt-get install language-pack-kde-zh-hant-base

__Windows support__
Microsoft done this at 2013, we should consider support this change:
.NET Framework 4 in 2013: What's New in Globalization and Localization