Code style adherence, mostly whitespace changes.

* Spaces to tabs.
* Some removal of empty lines where code is a bit to sparse, and
insertion where a bit too dense.
* Reflow a couple of code comments.
* Remove any trailing whitespace.
Style and typography fixes.

* Curly apostrophes and quotation marks.
* Em dashes.
* Remove any trailing whitespace.
* Some capitalization.
* Additional inline code Markdown for mentions of function names etc.