cpp: Fix an OpenBSD compilation bug by moving a typedef

The typedef was aliasing a private type, which is apparently illegal.
Moving it into the class definition fixed it.

git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@776928 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/lib/cpp/src/concurrency/TimerManager.h b/lib/cpp/src/concurrency/TimerManager.h
index f3f799f..dfbf0ea 100644
--- a/lib/cpp/src/concurrency/TimerManager.h
+++ b/lib/cpp/src/concurrency/TimerManager.h
@@ -113,6 +113,8 @@
   friend class Dispatcher;
   boost::shared_ptr<Dispatcher> dispatcher_;
   boost::shared_ptr<Thread> dispatcherThread_;
+  typedef std::multimap<int64_t, boost::shared_ptr<TimerManager::Task> >::iterator task_iterator;
+  typedef std::pair<task_iterator, task_iterator> task_range;
 };
 
 }}} // apache::thrift::concurrency