+changes in sbcl-1.0.15 relative to sbcl-1.0.14:
+ * enhancement: cleaner backtraces for interactive interrupts, as
+ well as other cases where the interesting frames used to be
+ obscured by interrupt handling frames.
+ * bug fix: SORT was not interrupt safe.
+ * bug fix: XREF accounts for the last node of each basic-block as
+ well.
+