implement a summary line

For Pony's bot, implement a summary line that just shows the highlights of the log

EliteBGS/LogGenerator/MissionFormat.cs

@@ -76,4 +76,21 @@ public class MissionFormat : LogFormatter {
 
         return output.ToString().Trim();
     }
+
+    public string GenerateSummary(Objective objective) {
+        long influence = objective
+            .EnabledOfType<MissionCompleted>()
+            .Sum(x => x.Influence.Length)
+            ;
+        long support = objective
+            .EnabledOfType<InfluenceSupport>()
+            .Sum(x => x.Influence.Length)
+            ;
+
+        if (influence + support <= 0) {
+            return "";
+        }
+
+        return string.Format("INF: {0}", influence + support);
+    }
 }