Many, many changes but no real changes to content nor formatting.

Many, many changes but no real changes to content nor formatting.

- many spelling fixes
- various typo and punctuation fixes
- spell out digits as appropriate (help doc to be consistent)
- or use digits instead of words as appropriate
- fix some minor grammar issues
- mention "Linux" if referring to a Linux "kernel"
- proper use of a couple vendor names (to be consistent)

Okayed by Kern. (Note this does NOT include the TODO: nor \chapter changes.)