Major plugin refactor and cleanup.

Switched to POCO library for unified platform/library interface.
Deprecated the external module API. It was creating more problems than solving.
Removed most built-in libraries in favor of system libraries for easier maintenance.
Cleaned and secured code with help from static analyzers.

vendor/POCO/Foundation/include/Poco/NotificationStrategy.h

@@ -0,0 +1,112 @@
+//
+// NotificationStrategy.h
+//
+// Library: Foundation
+// Package: Events
+// Module:  NotificationStrategy
+//
+// Definition of the NotificationStrategy interface.
+//
+// Copyright (c) 2006-2011, Applied Informatics Software Engineering GmbH.
+// and Contributors.
+//
+// SPDX-License-Identifier:	BSL-1.0
+//
+
+
+#ifndef Foundation_NotificationStrategy_INCLUDED
+#define Foundation_NotificationStrategy_INCLUDED
+
+
+#include "Poco/Foundation.h"
+
+
+namespace Poco {
+
+
+template <class TArgs, class TDelegate> 
+class NotificationStrategy
+	/// The interface that all notification strategies must implement.
+	/// 
+	/// Note: Event is based on policy-driven design, so every strategy implementation
+	/// must provide all the methods from this interface (otherwise: compile errors)
+	/// but does not need to inherit from NotificationStrategy.
+{
+public:
+	using DelegateHandle = TDelegate*;
+
+	NotificationStrategy()
+	{
+	}
+
+	virtual ~NotificationStrategy()
+	{
+	}
+
+	virtual void notify(const void* sender, TArgs& arguments) = 0;
+		/// Sends a notification to all registered delegates.
+
+	virtual DelegateHandle add(const TDelegate& delegate) = 0;
+		/// Adds a delegate to the strategy.
+
+	virtual void remove(const TDelegate& delegate) = 0;
+		/// Removes a delegate from the strategy, if found.
+		/// Does nothing if the delegate has not been added.
+
+	virtual void remove(DelegateHandle delegateHandle) = 0;
+		/// Removes a delegate from the strategy, if found.
+		/// Does nothing if the delegate has not been added.
+
+	virtual void clear() = 0;
+		/// Removes all delegates from the strategy.
+
+	virtual bool empty() const = 0;
+		/// Returns false if the strategy contains at least one delegate.
+};
+
+
+template <class TDelegate> 
+class NotificationStrategy<void, TDelegate>
+	/// The interface that all notification strategies must implement.
+	/// 
+	/// Note: Event is based on policy-driven design, so every strategy implementation
+	/// must provide all the methods from this interface (otherwise: compile errors)
+	/// but does not need to inherit from NotificationStrategy.
+{
+public:
+	using DelegateHandle = TDelegate*;
+
+	NotificationStrategy()
+	{
+	}
+
+	virtual ~NotificationStrategy()
+	{
+	}
+
+	virtual void notify(const void* sender) = 0;
+		/// Sends a notification to all registered delegates.
+
+	virtual DelegateHandle add(const TDelegate& delegate) = 0;
+		/// Adds a delegate to the strategy.
+
+	virtual void remove(const TDelegate& delegate) = 0;
+		/// Removes a delegate from the strategy, if found.
+		/// Does nothing if the delegate has not been added.
+
+	virtual void remove(DelegateHandle delegateHandle) = 0;
+		/// Removes a delegate from the strategy, if found.
+		/// Does nothing if the delegate has not been added.
+
+	virtual void clear() = 0;
+		/// Removes all delegates from the strategy.
+
+	virtual bool empty() const = 0;
+		/// Returns false if the strategy contains at least one delegate.
+};
+
+
+} // namespace Poco
+
+
+#endif // Foundation_NotificationStrategy_INCLUDED