Adds three new languages:
- de_AT: German (Austria)
- gl: Galician
- sl_SI: Slovenian (Slovenia)
Updates many others.
Thanks to the translators contributing on Transifex!
- update translation master files
- include current translations from Transifex
- add several new languages
- fix a bug in bitcoin.qrc, which prevents some languages from beeing used
(wrong file extension .ts instead of .qm was used)
- added languages in bitcoin.qrc: bs, ca, cy, eo, gu_IN, hi_IN, ja, la,
lv_LV and th_TH (some translations files were already in src/qt/locale
but not added in the .qrc file