Get-Setf-Method

["Scott E. Fahlman" <Fahlman@CMU-CS-C.ARPA>]

        Get-Setf-Method should take an (optional?) environment argument so
    that it can expand macros correctly. 

Steve Handerson has pointed out that MACRO-FUNCTION also needs an
optional evironment argument, since without this we have no way of
getting hold of the expansion function for a lexically defined macro
(though we can execute this function).  This may or may not be important
for normal code, but it is definitely important for writing environment
tools such as a single-stepper.

-- Scott