rust-chg: upgrade to 2018 edition and remove useless extern crates
Differential Revision: https://phab.mercurial-scm.org/D8399
// Copyright 2018 Yuya Nishihara <yuya@tcha.org>
//
// This software may be used and distributed according to the terms of the
// GNU General Public License version 2 or any later version.
mod attachio;
mod clientext;
pub mod locator;
pub mod message;
pub mod procutil;
mod runcommand;
mod uihandler;
pub use clientext::ChgClientExt;
pub use uihandler::{ChgUiHandler, SystemHandler};