Autoloading macros.

[George J. Carrette <GJC at MIT-MC>]

In order to have autoloading macros in the compiler you have to do
[1] (DEFPROP FOO "FOO;BAR" AUTOLOAD)
[2] (DEFPROP FOO AUTOLOAD-MACRO MACRO)
where:

(DEFUN AUTOLOAD-MACRO (FORM)
  (REMPROP (CAR FORM) 'MACRO)
  (LOAD (GET (CAR FORM) 'AUTOLOAD))
  (OR (GET (CAR FORM) 'MACRO) (ERROR "Macro not autoloaded" (CAR FORM)))
  FORM)