bitcoin support for formatter and parser

[frederikbosch]

Fixes #97.

@thedavidmeister Would you please have a look at this PR? I have never done anything with bitcoins. Actually, I have no clue how to parse and/or formatter this currency. I just had a lookup what the currency code is and how a bitcoin symbol looks like. I would really appreciate your feedback. Of course, anyone else can give feedback too.

[sagikazarmark]

Does Bitcoin support subunits?

[frederikbosch]

Some forum said it does, even up to 8 fractions at this moment

[sagikazarmark]

Ok, thanks

[frederikbosch]

@sagikazarmark https://millybitcoin.com/can-i-buy-a-fraction-of-a-bitcoin/ was my source. Just to repeat: I do not have any knowledge in the Bitcoin field. If other solutions are better, please suggest. I would not merge this, until someone with Bitcoin knowledge has approved this.

[frederikbosch]

Regarding code style: I do know if I am happy with one constant in the formatter and one constant in the parser. Maybe there should be a separate object. What do you think @sagikazarmark?

[sagikazarmark]

I am fine with the constant

[frederikbosch]

This can perfectly wait for 3.1.0 or 3.0.1.

[sagikazarmark]

In that case: can you resubmit the PR against master as soon as I renamed nextrelease to master?

[frederikbosch]

Sure, happy to do so. This was just a maintenance PR.