Changed default mean molecular weight re: a hint in problem 3 and Meghin's tip.
Some vestigial plotting infrastructure that I will never use.
Removed vestigial components.
Outlined the functions I'm about to use.
Wrote most of the functions. Mostly untested (but it compiles.)
Overhauled a lot of the functions to work better, units, etc.
Wrote Problem 3b function.
CLeaned up some comments.