5.3.0

[+] display PayPal buttons on Sign up step in checkout
[+] advanced display mode for PayPal buttons: display via native hooks or widget code
[+] customization of the styles for PayPal buttons: color, shape, size, label
[+] added information about maintenance mode and TLS
[+] alert message about rounding settings
[+] added combinations reference to the transaction details on PayPal
[* ] updated PayPal benefits
[* ] fixed issues with onboarding
[* ] fixed issue with partial refund option
[* ] fixed issue with modified products in cart
[* ] fixed issue with ISO codes in lowercase ("The value of a field does not conform to the expected format" error)
[* ] minor fixes