implement Estonian identity verification

[chadwhitacre]

While considering evolving our corporate structure, we learned about Estonia's next-gen national identity implementation (and now I'm an e-Resident! :). They have a much cleaner solution to national identity verification than the current ugly hackish kludge of cross-checking passports through identity wholesalers (#2449). It's still early days for this, but it seems not unlikely to be the future—Kaspar reported at OuiShare Fest that he knows of "five countries who are copying this at the moment."

I want to verify my identity on Gratipay using my Estonian e-Resident smart card!

[techtonik]

Nice. If we have a link how to legally receive funds from Gratipay LLC. in Estonia (pay taxes etc.) - that would help a lot to get more users from this country.