Split the packages of language-*-zh

Currently many packages of Traditional Chinese(zh-TW) and Simplified Chinese(zh-CN) translations is combined in one language-*-zh, thus results people who does not need zh-CN or vice versa have to download and install unnecessary large amount of files and waste their time and disk space. These packages should be separated, e.g. language-support-zh, language-pack-zh, language-pack-gnome-zh, and language-pack-kde-zh, etc.