dirstate-tree: Empty shell for a second Rust DirstateMap implementation For background see description of the previous changeset "Make Rust DirstateMap bindings go through a trait object". Add an empty shell for a opt-in second Rust implementation of the `DirstateMap` type and the `status` function. For now all methods panic. This can be seen in "action" with: ./hg status --config experimental.dirstate-tree.in-memory=1 Differential Revision: https://phab.mercurial-scm.org/D10364

// config.rs
//
// Copyright 2020
//      Valentin Gatien-Baron,
//      Raphaël Gomès <rgomes@octobus.net>
//
// This software may be used and distributed according to the terms of the
// GNU General Public License version 2 or any later version.

//! Mercurial config parsing and interfaces.

mod config;
mod layer;
mod values;
pub use config::{Config, ConfigValueParseError};
pub use layer::{ConfigError, ConfigParseError};