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/XML/samples/samples.progen

@@ -0,0 +1,8 @@
+vc.project.platforms = Win32
+vc.project.configurations = debug_shared, release_shared, debug_static_mt, release_static_mt, debug_static_md, release_static_md
+vc.solution.create = true
+vc.solution.include = \
+	DOMParser\\DOMParser;\
+	DOMWriter\\DOMWriter;\
+	PrettyPrint\\PrettyPrint;\
+	SAXParser\\SAXParser