Add sync forceFlush and modified unit_test to be in working state again.

src/Synchronizer.cpp

@@ -205,7 +205,14 @@ void Synchronizer::periodicSync()
     while (!die)
     {
         lock.unlock();
-        boost::this_thread::sleep_for(syncInterval);
+        try
+        {
+            boost::this_thread::sleep_for(syncInterval);
+        }
+        catch (const boost::thread_interrupted)
+        {
+            //logger->log(LOG_DEBUG,"Synchronizer Force Flush.");
+        }
         lock.lock();
         //cout << "Sync'ing " << pendingOps.size() << " objects" << " queue size is " << 
         //    threadPool.currentQueueSize() << endl;
@@ -214,6 +221,13 @@ void Synchronizer::periodicSync()
     }
 }
 
+void Synchronizer::forceFlush()
+{
+    boost::unique_lock<boost::mutex> lock(mutex);
+    syncThread.interrupt();
+    lock.unlock();
+}
+
 void Synchronizer::makeJob(const string &key)
 {
     objNames.push_front(key);