refactor: invoice#66

ajax/products/calc.php

ajax/products/getProductEdit.php

ajax/products/hasProductCustomFields.php

ajax/products/parseProductToArticle.php

ajax/products/summary.php

bin/backend/classes/Sortable.css

bin/backend/classes/Sortable.js

bin/backend/controls/articles/Article.css

bin/backend/controls/articles/Article.html

bin/backend/controls/articles/Article.js

bin/backend/controls/articles/ArticleList.css

bin/backend/controls/articles/ArticleList.html

bin/backend/controls/articles/ArticleList.js

...nd/controls/articles/ArticleList.sortablePlaceholder.html

bin/backend/controls/articles/Text.css

bin/backend/controls/articles/Text.html

bin/backend/controls/articles/Text.js

...ls/articles/product/AddProductWindow.ProductSettings.html

bin/backend/controls/articles/product/AddProductWindow.css

bin/backend/controls/articles/product/AddProductWindow.js