Issues: IN-PACKAGE-FUNCTIONALITY and DEFPACKAGE

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

I like option 3, too. But I note that all kinds of packages are
going to be defined as just :USE LISP and nothing else, so that's
not enough safeguard to be completely sure that clobberage is not
occurring. I think we (Symbolics) will want to provide 
[implementation-dependent] support for complaining more forcefully
if the DEFPACKAGE is in a different file than the previous one
(to help us distinguish re-loading from clobbering back and forth),
so try to leave the wording vague enough to accomodate discretion
about exactly why the error might be signalled in the case of 
redefinition.