Update current translations, and add new languages:
- es_MX: Spanish (Mexico)
- pam: Kapampangan
Also update translation process for autoconf-based build system.
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)
