updated spec on SAIL

[Linda DeMichiel <LGD@SAIL.STANFORD.EDU>]

I have made a few minor edits to the drafts of the concepts and functions
chapters that Sonya put out on SAIL last month.  The only changes of note
here are some corrections to the new standard-type-class/superclasses
table in the section "Integrating Types and Classes."
I also tweaked the macros file so that it now prints "Draft" and the date,
so that we can keep our hardcopy drafts straight while we work.
There are also new .dvi files available.

--lgd