aldor tests: Add a testcase reflecting issue #91
Add workaround for bug #91.. make sure there is a nice visible reference to
'% has CopyableType' at the top level of the default body.
Add rules to run tests enclosed by #if ALDORTEST in the aldor and algebra
libraries.  Currently just runs vs the interpreter, so a couple (sal_cmdline
and a gmp test) fail.
bint.c: Add some paranoia regarding sizeof(long) and sizeof(UNotAsLong).

Check for bad configurations in tests and library.  Also, look for
const in cconfig.h
algebra: Be a little more careful when testing gcds - gcd(0, 0) is undefined
so automatically pass in this case.  Also, preserve result of test properly.
aldortest: Tests should fail with an exception, rather than just
printing "error"

This should enable make check to work better.