<huge_val.h> and more

[Stephen Weeks]

> Thanks for the details.  By the way, i built mlton on a linux box and
> played with it just a little bit.  I am familiar with the caml variant
> of ML but not the particulars of sml.

I'm glad that the install went smoothly.  Just a word of warning,
which is also made in the user guide: I recommend against doing
program development with MLton since it's error detection and
reporting facilities are either nonexistent or terrible.  MLton is
really just intended as an optimizing compiler once you've got your
SML program working.  If you want to play around with learning SML you
should probably use the ML Kit.