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/NetSSL_OpenSSL/Makefile

@@ -0,0 +1,26 @@
+#
+# Makefile
+#
+# Makefile for Poco NetSSL_OpenSSL
+#
+
+include $(POCO_BASE)/build/rules/global
+
+SYSLIBS += -lssl -lcrypto
+
+objects = AcceptCertificateHandler RejectCertificateHandler ConsoleCertificateHandler \
+	CertificateHandlerFactory CertificateHandlerFactoryMgr \
+	Context HTTPSClientSession HTTPSStreamFactory HTTPSSessionInstantiator \
+	InvalidCertificateHandler KeyConsoleHandler \
+	KeyFileHandler PrivateKeyFactory PrivateKeyFactoryMgr \
+	PrivateKeyPassphraseHandler SecureServerSocket SecureServerSocketImpl \
+	SecureSocketImpl SecureStreamSocket SecureStreamSocketImpl \
+	SSLException SSLManager Utility VerificationErrorArgs \
+	X509Certificate Session SecureSMTPClientSession \
+	FTPSClientSession FTPSStreamFactory
+
+target         = PocoNetSSL
+target_version = $(LIBVERSION)
+target_libs    = PocoNet PocoCrypto PocoUtil PocoFoundation
+
+include $(POCO_BASE)/build/rules/lib