Added an order_totals_context tag that only puts item_total, totals and total into (current block) template context.
In some cases neither the html nor the text template is suitable, but one still wants to output the same data.
Implemented loyalty discounts, a discount flavour taking into consideration former orders of a customer, but not requiring entering a code.
Merge branch 'feature/loyalty-discounts' into develop

Conflicts:
	cartridge/shop/admin.py
	cartridge/shop/models.py
	cartridge/shop/translation.py
PEP8, line too long.
Merge branch 'feature/loyalty-discounts' into develop