Updated mediawiki/extensions
Project: mediawiki/extensions/BlueSpiceExtensions  71dfca785c5b566fb1e6cc13fca041cf9d450b94

Implemented changes for translatewiki

Moved to Json i18n files
Use image instead of picture for better consistency
Changed filename, filetypes to file name, file types
Improved messages better punctuation
Removed unused message
Removed deprecated file
Changed message key

Change-Id: I34e6d509ea1b67c7ad2eb17489dc1be597092701