Fix examples/machine-code/garbage-collectors for tight equality

Finish fixing machine-code for new by

build --selftest=3 now completes; I'm ready to merge into master.

Build more machine-code example thys with pat_assum

Get cheney_allocTheory to build in mem-abbrev world.

Progress with #52.

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?

A new version of files previously in examples/mc-logic.
Eventually examples/mc-logic will be deleted.