* Fix - INTENT_MISMATCH errors when guest customers save a card and registration is disabled.
* Fix - Improve checkout compatibility with password managers such as 1Password. This also avoids payment for reload on address change.
* Fix - Pass valid address values even if checkout fields are not present.
* Tweak - Sandbox mode can be turned on in the settings, no more need for setting the constant.
* Tweak - Change location URL to refer to our docs.