New french string + "$ignored_files"

3 minor changes:

- Some extra (missing) french translations
- Add .svg and .svgz to the list of allowed images
- Add a $ignored_files array to hide/skip unwanted files

By default, the ignored files (in the default config.php files) are: '.svn', '.git', '.cvs', '.CVS', '.~', '.DS_Store', 'thumbs.db', 'Thumbs.db', 'desktop.ini'