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/URIStreamFactory.h

@@ -0,0 +1,97 @@
+//
+// URIStreamFactory.h
+//
+// Library: Foundation
+// Package: URI
+// Module:  URIStreamFactory
+//
+// Definition of the URIStreamFactory class.
+//
+// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
+// and Contributors.
+//
+// SPDX-License-Identifier:	BSL-1.0
+//
+
+
+#ifndef Foundation_URIStreamFactory_INCLUDED
+#define Foundation_URIStreamFactory_INCLUDED
+
+
+#include "Poco/Foundation.h"
+#include <istream>
+
+
+namespace Poco {
+
+
+class URI;
+
+
+class Foundation_API URIStreamFactory
+	/// This class defines the interface that all
+	/// URI stream factories must implement.
+	///
+	/// Subclasses must implement the open() method.
+{
+public:
+	URIStreamFactory();
+		/// Creates the URIStreamFactory.
+
+	virtual std::istream* open(const URI& uri) = 0;
+		/// Tries to create and open an input stream for the
+		/// resource specified by the given URI.
+		///
+		/// If the stream cannot be opened for whatever reason,
+		/// an appropriate IOException must be thrown.
+		///
+		/// If opening the stream results in a redirect, a
+		/// URIRedirection exception should be thrown.
+
+protected:
+	virtual ~URIStreamFactory();
+		/// Destroys the URIStreamFactory.
+
+private:
+	URIStreamFactory(const URIStreamFactory&);
+	URIStreamFactory& operator = (const URIStreamFactory&);
+	
+	friend class URIStreamOpener;
+};
+
+
+class Foundation_API URIRedirection
+	/// An instance of URIRedirection is thrown by a URIStreamFactory::open()
+	/// if opening the original URI resulted in a redirection response
+	/// (such as a MOVED PERMANENTLY in HTTP).
+{
+public:
+	URIRedirection(const std::string& uri);
+	URIRedirection(const URIRedirection& redir);
+	
+	URIRedirection& operator = (const URIRedirection& redir);
+	void swap(URIRedirection& redir);
+	
+	const std::string& uri() const;
+		/// Returns the new URI.
+	
+private:
+	URIRedirection();
+	
+	std::string _uri;
+};
+
+
+//
+// inlines
+//
+inline const std::string& URIRedirection::uri() const
+{
+	return _uri;
+}
+
+
+} // namespace Poco
+
+
+#endif // Foundation_URIStreamFactory_INCLUDED