EIP4907: ERC-721 User And Expires Extension

[0xanders]

@CarlosTM

Add a new function to renew the loan (NewExpiresOf) and keep the ExpiresOf to check how long the first date lasted for the new date, this could be a new condition to allow interest in the future.

Thanks for your feedback. Because the status of ERC-4907 is Final, you could propose a new EIP as extension of ERC-4907 to add this new function.