v3.6.5: Bugfixes

This release contains changes associated with the following GitHub issues:

#342: Preserve listing filters in listings' display-order form.
#344: Correct "Missing constant" logs for zc158 on the products_all page.
#343: Add display-order selection for products' and specials' listings (zc200 or later, only).
#349: Use zen_get_products_name to display products' names in listings.
#345: Correct products' table formatting on the AJAX checkout_payment page.
#352: Change products items title from heading to paragraph for accessibility.
#353: Enable the zca_splitPageResults class to be overridden.
#355: Provide title HTML attributes on header-navigation links.
#356: Always display the "Home" link in the header; ensure header-messages are displayed even if the header is disabled.