Add a statistical profiler. Also applied a bugfix b3Profiler.

- This is a compact hierarchical profiler which also stores node statistics
- Might need to use a hash-table to lookup statistic for node because each frame trees are build

examples/testbed/framework/profiler.cpp

@@ -127,12 +127,13 @@ void Profiler::End()
 		listener->BeginEvents();
 	}
 
-	RecurseEvents(m_root);
-	
-	RecurseDestroyNode(m_root);
-	m_root = nullptr;
+	if (m_root)
+	{
+		RecurseEvents(m_root);
 
-	assert(m_root == nullptr);
+		RecurseDestroyNode(m_root);
+		m_root = nullptr;
+	}
 
 	if (listener)
 	{