Fixed *x* and the like for Chapter 4
More *x* catches in CMA05-5 and CMA05-6
Appendix link added in Chapter 2
Overhaul Chapter 4

Overhaul:

Check -full on MathJax
Add Appendix to Nav
new norm in navigation
trade ' in nav &#8217;
look at ref in exercises
Add text roman to all lists
Check refs in chapter 2
Save as you go