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/PDF/PDF.progen

@@ -0,0 +1,16 @@
+vc.project.guid = E12E5C71-79A4-495A-848F-F1710111E610
+vc.project.name = PDF
+vc.project.target = Poco${vc.project.name}
+vc.project.type = library
+vc.project.pocobase = ..
+vc.project.outdir = ${vc.project.pocobase}
+vc.project.platforms = Win32
+vc.project.configurations = debug_shared, release_shared, debug_static_mt, release_static_mt, debug_static_md, release_static_md
+vc.project.prototype = ${vc.project.name}_vs90.vcproj
+vc.project.compiler.include = .\\include\\Poco\\PDF;..\\Foundation\\include;..\\XML\\include;..\\Util\\include
+vc.project.compiler.defines =
+vc.project.compiler.defines.shared = _CRT_SECURE_NO_WARNINGS;${vc.project.name}_EXPORTS
+vc.project.compiler.defines.debug_shared = ${vc.project.compiler.defines.shared}
+vc.project.compiler.defines.release_shared = ${vc.project.compiler.defines.shared}
+vc.solution.create = true
+vc.solution.include = testsuite\\TestSuite