changes in sbcl-1.4.16 relative to sbcl-1.4.15:
* minor incompatible change: ENSURE-DIRECTORIES-EXIST no longer establishes
a CONTINUE restart in case of an error.
* minor incompatible change: Defining macros (DEFVAR, etc) which require a
symbol as the name will fail to macroexpand if given a non-symbol.
* enhancement: the unexported restart names SB-{ALIEN,FASL,IMPL,PCL}::RETRY
have been replaced by SB-EXT:RETRY.