Sync translations with Transifex

Signed-off-by: Sven Strickroth <email@cs-ware.de>
Prepare release and bump version numbers to 1.8.12.0

Signed-off-by: Sven Strickroth <email@cs-ware.de>
Fixed issue #2359: Selected files counter not updated after revert

Signed-off-by: Sup Yut Sum <ch3cooli@gmail.com>