Bitcoin implementation

[da2x]

First iteration will not suggest an amount, but wallet addresses will be collected and stored, and a Bitcoin payment link will be inclueded on the payment list.

I’m not sure how to suggest an amount for such an unstable currency. What is worth 10 USD one day is worth 600 USD the next. Leaving the field empty for now.

Can discover from document or from /tipsy.txt.

This pull request adds Bitcoin support to the generators.

[rht]

Raw Bitcoin URI (instead of dressed with BIP 70/75) allows permissionless payments. As much as Bitcoin transaction is traceable and de-anonymizeable, in some cases (when the site is an org, e.g. Wikipedia, instead of a personal site hosted by another entity) or in some states, the sender info is required and there might be legal complications otherwise. The documentation needed might be lengthy. Though in either case, whether the site is owned by an org or personal entity, or whether the org is registered on top of a land with a specific cryptocurrency regulation, could be automatically checked and handled.

The payment processor in some "web wallets" (e.g. Coinbase) does have the on-the-fly conversion from fiat.

[da2x]

In some countries it’s also illegal to use PayPal … . That discussion is kind of out-of-scope here.