[gambit-list] |it| in the repl

[Christian]

This patch has the ugly side effect that gambit's search algorithm 
for functions is "broken", it now always returns 'it (or 'it1 etc.) 
as the name of a function:

>  error
#<procedure #2 it>
>  error
#<procedure #2 it1>

So a solution which binds 'it lexically would be better also because 
of this issue.

Christian.