Re: pika 0.1pre4 -- equality, hashing, symbols

I just resync'd with your branch and running 'make test' failed one of
the unit tests:

================ unit-hash-value tests ================
/home/jivera/wd/pika-0.1pre2/src/scm/tests/hash-value-tests/unit-hash-value.c:149:botched invariant
    hashq_values[x] != hashq_values[y]
PANIC: exiting on botched invariant

I'll take a look at it, but I haven't grokked the hashing code yet
(and I know I haven't touched it in my branch at all yet).

-jivera