Issue: APPLYHOOK-ENVIRONMENT (Version 2)

[Kent M Pitman <KMP@STONY-BROOK.SCRC.Symbolics.COM>]

[X3J13 removed.]

For compatibility, we might want to consider either explicitly
permitting implementations to accept a third optional argument
to APPLYHOOK, which would be defined to be ignored, or else
actually require implementations to accept such an argument.

In the Cost to Users, you should highlight that the reason for
making the third argument optional is only for source compatibility
with CLtL. There should be no doubt that the value of *APPLYHOOK*
will only receive only two arguments.

Anyway, I approve of this proposal, whether the writeup is 
ultimately ammended or not.