Align the SimplestCase single host sample with the multi host example. (

#235)

- make the "from the start" position argument conform to the contract (AeronArchive.NULL_POSITION)
 - wait for the counter to become available instead of assuming that it is immediately available ( as it sometimes resulted in error when attempted to read too early).
 - fix shut down behaviour by attempting to close the resources even if the exception occurred. It used to hang forever by not executing close logic on exception.

archive-core/src/main/java/com/aeroncookbook/archive/SimplestCase.java

@@ -62,12 +62,18 @@ public class SimplestCase
     public static void main(final String[] args)
     {
         final SimplestCase simplestCase = new SimplestCase();
-        simplestCase.setup();
-        LOGGER.info("Writing");
-        simplestCase.write();
-        LOGGER.info("Reading");
-        simplestCase.read();
-        simplestCase.cleanUp();
+        try
+        {
+            simplestCase.setup();
+            LOGGER.info("Writing");
+            simplestCase.write();
+            LOGGER.info("Reading");
+            simplestCase.read();
+        }
+        finally
+        {
+            simplestCase.cleanUp();
+        }
     }
 
     private void cleanUp()
@@ -85,7 +91,7 @@ private void read()
             .aeron(aeron)))
         {
             final long recordingId = findLatestRecording(reader, channel, streamCapture);
-            final long position = 0L;
+            final long position = AeronArchive.NULL_POSITION;
             final long length = Long.MAX_VALUE;
 
             final long sessionId = reader.startReplay(recordingId, position, length, channel, streamReplay);
@@ -128,7 +134,12 @@ private void write()
 
             final long stopPosition = publication.position();
             final CountersReader countersReader = aeron.countersReader();
-            final int counterId = RecordingPos.findCounterIdBySession(countersReader, publication.sessionId());
+            int counterId = RecordingPos.findCounterIdBySession(countersReader, publication.sessionId());
+            while (CountersReader.NULL_COUNTER_ID == counterId)
+            {
+                idleStrategy.idle();
+                counterId = RecordingPos.findCounterIdBySession(countersReader, publication.sessionId());
+            }
 
             while (countersReader.getCounterValue(counterId) < stopPosition)
             {