Add custom panic hook

The panic hook prints a backtrace, the panic message, file, and line
number, and a plea to report bugs.

ethstore/cli/Cargo.toml

@@ -9,6 +9,7 @@ serde = "1.0"
 serde_derive = "1.0"
 docopt = "0.8"
 ethstore = { path = "../" }
+panic_hook = { path = "../../panic_hook" }
 
 [[bin]]
 name = "ethstore"

ethstore/cli/src/main.rs

@@ -20,6 +20,7 @@ extern crate serde;
 #[macro_use]
 extern crate serde_derive;
 extern crate ethstore;
+extern crate panic_hook;
 
 use std::{env, process, fs, fmt};
 use std::io::Read;
@@ -134,6 +135,8 @@ impl fmt::Display for Error {
 }
 
 fn main() {
+	panic_hook::set();
+
 	match execute(env::args()) {
 		Ok(result) => println!("{}", result),
 		Err(err) => {