revised MARK book chapters

Fairly major additions/revisions to Chapter 9 (multi-state models), and Chapter 12 (individual covariates chapter). The changes in chapter 9 have to do with new approaches to testing for local minima, while changes in Chapter 12 discuss fundamental changes in how covariate standardization is handled in MARK.
Probably worth downloading these two revised chapters.
Probably worth downloading these two revised chapters.