Added menu option to send CTRL-ALT-DELETE to emulated machine. Patch from GeeDee.

src/pc.c

@@ -277,6 +277,16 @@ void resetpc()
         shadowbios=0;
 }
 
+void resetpc_cad()
+{
+	keyboard_send(29);	/* Ctrl key pressed */
+	keyboard_send(56);	/* Alt key pressed */
+	keyboard_send(83);	/* Delete key pressed */
+	keyboard_send(157);	/* Ctrl key released */
+	keyboard_send(184);	/* Alt key released */
+	keyboard_send(211);	/* Delete key released */
+}
+
 void resetpchard()
 {
         device_close_all();