Added remove_articles to make ArticleSet more consistent
Added remove_articles to make ArticleSet more consistent

tschmorleiz/amcat,amcat/amcat,tschmorleiz/amcat,tschmorleiz/amcat,amcat/amcat,amcat/amcat,tschmorleiz/amcat,amcat/amcat,amcat/amcat,tschmorleiz/amcat,amcat/amcat