sawsim/discussion.tex: Add D_JS, D_KL, p_m, ... to the nomenclature

sawsim/discussion.tex: Add D_JS, D_KL, p_m, ... to the nomenclature

Thanks Mom!

Also:
* Add chi-squared and D_chi-squared to the nomenclature
* Fix hyphen -> en-dash in Kullback--Leibler
* Label eq:sawsim:p_m (so it can be referenced from the index)
* Fix UTF-8 chi -> \chi
* Remove a dangling close-paren from eq:sawsim:X2
* Cite NIST for the chi-square comparison
* Break Gumbel and chi-squared citations into @inbook
* Add editors for the new NIST:ESH book entry