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/ProGen/templates/vs160/Win32/executable/project.properties

@@ -0,0 +1,12 @@
+project.suffix = _vs160.vcproj
+project.targetSuffix.debug_shared = d
+project.targetSuffix.release_shared =
+project.targetSuffix.debug_static_md = d
+project.targetSuffix.release_static_md =
+project.targetSuffix.debug_static_mt = d
+project.targetSuffix.release_static_mt =
+project.postprocess = upgrade2008to2019
+project.finalSuffix = _vs160.vcxproj
+project.architectures = Win32, x64
+project.targetArchitecture.Win32 = IA32
+project.targetArchitecture.x64 = AMD64