OCaml Format pretty-printer combinators

Fmt exposes combinators to devise `Format` pretty-printing functions.

Fmt depends only on the OCaml standard library. The optional `Fmt_tty`
library that allows to setup formatters for terminal color output
depends on the Unix library. The optional `Fmt_cli` library that
provides command line support for Fmt depends on [`Cmdliner`][cmdliner].

Fmt is distributed under the ISC license.

[cmdliner]: http://erratique.ch/software/cmdliner
