Section 7.2 Edits, some rewrites also TOC

Attempted to make this section more simple in tougher areas.  No meaning
changes intended, only clarification.  Re-sectioned as well, so will
affect table of contents
Fixed line length issues
Added requirements where missing, period, line spacing fixed
Merge pull request #383 from andyjohnson/7.2edits

Section 7.2 Edits, some rewrites also TOC