Minor tweaks.

Removed trailing whitespace from all .sml and .sig files.

This affects over 900 files and was done using emacs's delete-trailing-whitespace
function in batch mode. Building the system with Poly/ML and Moscow ML seems to
work, so I'm hoping these changes don't break anything. Please complain if
they do!

A general update. Now lisp_finalTheory produces assembly files
containing the verified LISP interpeteres (in machine code):

arm_eval.s
x86_eval.s
ppc_eval.s

Each of these have been successfully run on real hardware, for
each respective platform.

The proof scripts are likely to only work in the experimental
kernel, due to some unfortuante differences between the two
kernels. Some of these differences are exposed more frequently
now due to recent(ish) changes to the datatype package. Maybe
some of the changes made to the datatype package ought to be
reconsidered?

Improvements to the verified LISP interepreters.

The new interpreters have been proved to implement
McCarthy's LISP 1.5 as formalise by Mike Gordon
for the ACL2 workshop 2007.

Warning: lisp_evalScript takes 73 minutes to run
using Holmake under PolyML.