Feature translation update

I recently working on the translation issue. I write a script PyLinguist to helping translation using google translate (thanks the helping by global667):
https://github.com/yodalee/PyLinguist
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Actually this pull request is not about this script.
It's just a little modification on translation directory:
* use recursive mechanism of lupdate in translation Makefile
* add a untranslated version of qucs_ts, actually I'm not quite sure is this necessary or not