* change language tag from data-lang to lang to enable spell checking
See https://www.w3.org/International/questions/qa-html-language-declarations for reference
* change language tag from data-lang to lang in correspondence to i18n.py
change necessary to enable spell checking in textareas
In the order overview the total of "paid orders" is the same as the total number of "ordered items". By using the right variable, we can easily fix that ;)