Code style fixes.

* Single quotes to double quotes.
* Spaces to tabs.
* Whitespace fixes inside parentheses etc.
* Some empty line insertions and removals.
Style and typography fixes.

* Remove double-spaces after periods.
* Remove trailing whitespace.
* Curly apostrophes and quotation marks.
* Em dashes.
* Additional inline code markup of function/property names.
* Move footnote style Markdown links to inline style.
* Replace stray .note divs with Markdown.
* Replace HTML list block with Markdown equivalent.
No entities.