This is ported to ABCL (and MCL) from the version on google code,
which was written in Allegro common lisp.

I've turned off the DIG processor and the command line processing.

There were a couple of things I needed to do to make it run in MCL and
ABCL.

1) Use of eq to compare numbers. This isn't portable and breaks in
ABCL. Fix was to change all occurrences of "(eq " to "(eql " and
all occurrences of ":test 'eq" to ":test 'eql"

2) There was an error in the definition of the defstruct
(internal-data-structure). Several of the fields are initialized with
nil, but are declared to be type cons. They were changed to be type
list as nil is not a cons.

In addition there are some places that were conditionalized so that
they don't use allegro internals. the "excl:quit" function comes to
mind.