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/SHA1Engine.h

@@ -0,0 +1,81 @@
+//
+// SHA1Engine.h
+//
+// Library: Foundation
+// Package: Crypt
+// Module:  SHA1Engine
+//
+// Definition of class SHA1Engine.
+//
+// Secure Hash Standard SHA-1 algorithm
+// (FIPS 180-1, see http://www.itl.nist.gov/fipspubs/fip180-1.htm)
+//
+// Based on the public domain implementation by Peter C. Gutmann
+// on 2 Sep 1992, modified by Carl Ellison to be SHA-1.
+//
+// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
+// and Contributors.
+//
+// SPDX-License-Identifier:	BSL-1.0
+//
+
+
+#ifndef Foundation_SHA1Engine_INCLUDED
+#define Foundation_SHA1Engine_INCLUDED
+
+
+#include "Poco/Foundation.h"
+#include "Poco/DigestEngine.h"
+
+
+namespace Poco {
+
+
+class Foundation_API SHA1Engine: public DigestEngine
+	/// This class implements the SHA-1 message digest algorithm.
+	/// (FIPS 180-1, see http://www.itl.nist.gov/fipspubs/fip180-1.htm)
+{
+public:
+	enum
+	{
+		BLOCK_SIZE  = 64,
+		DIGEST_SIZE = 20
+	};
+
+	SHA1Engine();
+	~SHA1Engine();
+		
+	std::size_t digestLength() const;
+	void reset();
+	const DigestEngine::Digest& digest();
+
+protected:
+	void updateImpl(const void* data, std::size_t length);
+
+private:
+	void transform();
+	static void byteReverse(UInt32* buffer, int byteCount);
+
+	typedef UInt8 BYTE;
+
+	struct Context
+	{
+		UInt32 digest[5]; // Message digest
+		UInt32 countLo;   // 64-bit bit count
+		UInt32 countHi;
+		UInt32 data[16];  // SHA data buffer
+		UInt32 slop;      // # of bytes saved in data[]
+	};
+
+	Context _context;
+	DigestEngine::Digest _digest;
+
+	SHA1Engine(const SHA1Engine&);
+	SHA1Engine& operator = (const SHA1Engine&);
+};
+
+
+} // namespace Poco
+
+
+#endif // Foundation_SHA1Engine_INCLUDED