Markdown: Fix classifier ordering conflict

Don't try to use HtmlClassifier before it exists.
Markdown: Remove HTML code Artifact special-casing

I need to find a different approach to handle HTML
Markdown: Try manually fixing nested HTMLX buffers

Doesn't work yet...
Analysis: (CA1822) Mark members as static.
Cleanup: Various fixes.

- Reverted recent CA1822 changes.
- Bundle xml needs to be trimmer before loading.
Analysis: (CA1702) Compound words cased correctly.
Analysis: (CA1030) Use events where appropriate.
Analysis: (CA1063) Implement IDisposable correctly.
Cleanup: Organize using.