Insert explicit warning into the panic hook

parity/main.rs

@@ -285,6 +285,7 @@ fn main_direct(force_can_restart: bool) -> i32 {
 					let e = exit.clone();
 					let exiting = exiting.clone();
 					move |panic_msg| {
+						warn!("Panic occured, see stderr for details");
 						eprintln!("{}", panic_msg);
 						if !exiting.swap(true, Ordering::SeqCst) {
 							*e.0.lock() = ExitStatus {