+ ** CONVERT-MORE-CALL failed on a lambda list (&KEY); (thanks to
+ Gerd Moellmann)
+ ** &WHOLE and &REST arguments in macro lambda lists are patterns;
+ ** NSET-EXCLUSIVE-OR does not return extra elements when its
+ arguments contain duplicated elements;
+ ** RESTART-CASE understands local macros;
+ ** ... and associates exactly its own restarts with a condition;
+ ** ENDP in safe mode checks its argument to be of type LIST;
+ ** COPY-SYMBOL in a threaded build no longer fails when the symbol
+ in question is unbound;