implement localizations based on punic

fixes https://github.com/owncloud/core/issues/5128

Finally we get proper localizations for all languages independent of installed locales on the target system

@karlitschek @PVince81 @icewind1991 @butonic @bantu @LukasReschke Please review - THX

Requires https://github.com/owncloud/3rdparty/pull/127