+ * enhancement: BACKTRACE and DESCRIBE now bind *PRINT-CIRCLE* to T, and
+ generally behave better when errors occur during printing.
+ * enhancement: the test runner now takes a --report-skipped-tests argument
+ to report the individual tests skipped as well as the number of skipped
+ tests.
+ * enhancement: undefined functions now appear in backtraces as ("undefined
+ function") instead of ("bogus stack frame") on x86oids.