Allow donating via BTC or other crypto

[squigglezworth]

Several people have expressed desire to donate via Bitcoins.

While this may take some setup, with exchanges and how popular BTC is these days, I think this is a good idea, and shouldn't be that troublesome.

BTC and LTC should be accepted at least as they are most used cryptocurrencies nowadays.

coinpayments.net has low fees and is very easy to setup as a payment merchant for site.

Alternatively, there are many public API's (for both LTC and BTC) that can be used to check wallet balances and transactions in order to integrate automatic payments on the site.