TrackedRace: distinguishing between start time determined with or without inference from start mark passings;

this allows us to use only start times *without* start mark passing inference in the mark passing calculator
which otherwise would lead to a conceptual recursion where mark passings may be excluded because other mark
passings have previously been inferred at a later point, suggesting a later start, ruling out earlier start
mark passings.

Change-Id: I9b5a530e388bfbc3e0fb91845ec892f288d403bd

java/com.sap.sailing.server/src/com/sap/sailing/server/masterdata/DummyTrackedRace.java

@@ -101,6 +101,11 @@ public class DummyTrackedRace extends TrackedRaceWithWindEssentials {
         return null;
     }
 
+    @Override
+    public TimePoint getStartOfRace(boolean inferred) {
+        return null;
+    }
+
     @Override
     public TimePoint getEndOfRace() {
         return null;