Black box: the queries of the user's train worked out once a read, lights as the driver checks them

- The stations, the signals passed, the horn points, the couplings, the
  consists and the timetable progress of the user's train are kept until
  a read adds something; the views asked for them every frame, which on
  a long session with many trains took the window down. A read that adds
  nothing no longer counts as a change.
- The lights are checked against the lamps the vehicles at the ends have
  (written by the simulator from now on), as its driver checks them: Pc 1
  without the upper headlight, with the auxiliary lamps, Pc 5 with the
  rear-end signals. Only while the user drives: the autopilot's lights
  are its own.
- A train off the platform counts at both ends: its head past the stop
  point as well as its tail before the platform's end.
- A recording without the couplings keeps the timetable for any vehicle
  of the user.
- A signal passed at danger is ringed on the map only once it was.
- In the tapes window a black box opens on a click or Enter, not when
  the arrow keys go over it.
- The viewer's screenshot of a window not laid out saves nothing and
  still closes.

Eu07.BlackBox/BlackBoxReader.cs

@@ -81,7 +81,8 @@ public sealed class BlackBoxReader
         }
 
         _offset += at;
-        Recording.Changed();
+        if (read > 0)
+            Recording.Changed();
         return read;
     }
 
@@ -161,6 +162,9 @@ public sealed class BlackBoxReader
                 // What the driver went by and the lights asked for came later still.
                 if (r.Remaining >= 5)
                     sample = sample with { Movement = (Movement)r.U8(), LightHintHead = (short)r.U16(), LightHintTail = (short)r.U16() };
+                // The lamps the vehicles at the ends have, which a pattern is checked against, later again.
+                if (r.Remaining >= 4)
+                    sample = sample with { EquippedHead = (Lights)r.U16(), EquippedTail = (Lights)r.U16() };
                 rec.AddCab(sample);
                 break;
             }