Fxed an issue with random encounters, added a repeatable property, add event for abandoning encounters

Runtime/IEncounterEvent.cs

@@ -24,4 +24,8 @@ namespace Jovian.EncounterSystem {
     public class GiveRewardEvent : IEncounterEvent {
         public Reward reward;
     }
+
+    [Serializable]
+    public class AbandonEncounterEvent : IEncounterEvent {
+    }
 }