Added a copy of the classic theme to be customized as 'cmsplugin_filer'.
Changed the filenames of the copied classic files.
Removed the minified theme file JS. It will be re-generated once the theme changes have been finished.
Replaced the name [Cc]lassic in all files with cmsplugin_filer.
Updated mtime + author.
Removed the black default background.
Use now the cmsplugin_filer theme as default theme for slideshows and don't show the folder name before the slideshow.
Removed slideshow.css. Styling is now provided via the galleria themes.
Corrected the theme path.