srogue: use functions from mdport.c.

Shell escape, passwd entries, terminal settings, and most signal
handling is now done with the more portable md_* functions.

srogue/mdport.c

@@ -210,6 +210,9 @@ md_onsignal_exit(void)
 #ifdef SIGTERM
     signal(SIGTERM, exit);
 #endif
+#ifdef SIGINT
+    signal(SIGINT, exit);
+#endif
 }
 
 extern void auto_save(int sig);