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/Util/Makefile

@@ -0,0 +1,36 @@
+#
+# Makefile
+#
+# Makefile for Poco Util
+#
+
+include $(POCO_BASE)/build/rules/global
+
+objects = AbstractConfiguration Application ConfigurationMapper \
+	ConfigurationView HelpFormatter IniFileConfiguration LayeredConfiguration \
+	LoggingConfigurator LoggingSubsystem MapConfiguration \
+	Option OptionException OptionProcessor OptionSet \
+	PropertyFileConfiguration Subsystem SystemConfiguration \
+	FilesystemConfiguration ServerApplication \
+	Validator IntValidator RegExpValidator OptionCallback \
+	Timer TimerTask
+
+ifeq ($(findstring MinGW, $(POCO_CONFIG)), MinGW)
+	objects += WinService WinRegistryKey WinRegistryConfiguration
+endif
+
+target         = PocoUtil
+target_version = $(LIBVERSION)
+target_libs    = PocoFoundation
+
+ifndef POCO_UTIL_NO_XMLCONFIGURATION
+objects     += XMLConfiguration
+target_libs += PocoXML
+endif
+
+ifndef POCO_UTIL_NO_JSONCONFIGURATION
+objects     += JSONConfiguration
+target_libs += PocoJSON
+endif
+
+include $(POCO_BASE)/build/rules/lib