merge some changes from develop branch; modernize and clean-up code; remove support for compiling without POCO_WIN32_UTF8

Foundation/include/Poco/Activity.h

@@ -82,7 +82,7 @@ public:
 		_runnable(*pOwner, method),
 		_stopped(true),
 		_running(false),
-		_done(false)
+		_done(Event::EVENT_MANUALRESET)
 		/// Creates the activity. Call start() to
 		/// start it.
 	{
@@ -134,8 +134,6 @@ public:
 	void stop()
 		/// Requests to stop the activity.
 	{
-		FastMutex::ScopedLock lock(_mutex);
-
 		_stopped = true;
 	}
 	
@@ -195,8 +193,8 @@ private:
 
 	C*                  _pOwner;
 	RunnableAdapterType _runnable;
-	volatile bool       _stopped;
-	volatile bool       _running;
+	std::atomic<bool>   _stopped;
+	std::atomic<bool>   _running;
 	Event               _done;
 	FastMutex           _mutex;
 };