support multiple file formats for article import

Conflicts:
	app/controllers/articles_controller.rb
	config/locales/de/de.articles.yml
	config/locales/en/en.articles.yml
update help text in upload form when switching file format

Conflicts:
	config/locales/de/de.articles.yml
	config/locales/en/en.articles.yml
fix import problem
autodetect csv separator on import

Conflicts:
	config/locales/de/de.articles.yml
	config/locales/en/en.articles.yml
fix foodsoft csv order (same as former situation)
fix article category matching
order categories by name in import parse_upload form