4f1200d629 Added `amount::Display` - configurable formatting (Martin Habovstiak)
Pull request description:
This significatnly refactors the formatting code to make formatting more
configurable. The main addition is the `Display` type which is a
builder that can configure denomination or other things (possibly more
in the future).
Further, this makes all representations of numbers minimal by default,
so should be documented as a possibly-breaking change.
Because of the effort to support all other `fmt::Formatter` options this
required practically complete rewrite of `fmt_satoshi_in`. As a
byproduct I took the opportunity of removing one allocation from there.
Closes#709
ACKs for top commit:
tcharding:
ACK 4f1200d629
dr-orlovsky:
ACK 4f1200d629
sanket1729:
ACK 4f1200d629
Tree-SHA512: 3fafdf63fd720fd4514e026e9d323ac45dfcd3d3a53a4943178b1e84e4cf7603cb6235ecd3989d46c4ae29453c4b0bb2f2a5996fbddf341cd3f68dc286062144
bcc923c03a