New timing infrastructure. There's a new function schedule_timer()

which pretty much any module can call to request a call-back in the
future. So terminal.c can do its own handling of blinking, visual
bells and deferred screen updates, without having to rely on
term_update() being called 50 times a second (fixes: pterm-timer);
and ssh.c and telnet.c both invoke a new module pinger.c which takes
care of sending keepalives, so they get sent uniformly in all front
ends (fixes: plink-keepalives, unix-keepalives).

[originally from svn r4906]
[this svn revision also touched putty-wishlist]

unix/pty.c

@@ -474,6 +474,8 @@ int pty_select_result(int fd, int event)
 #endif
 	    from_backend(pty_frontend, 0, message, strlen(message));
 	}
+
+	notify_remote_exit(pty_frontend);
     }
     return !finished;
 }