Guile and docs don't agree on :rename/:renamer module argument

[Matthias Koeppe]

doc/ref/scheme-modules.texi mentions that one can use the :rename
keyword argument in USE-MODULES module specs.

However, the implementation in ice-9/boot-9.scm (and the in-file
comments) call the keyword argument :renamer.  

Since the code does not check for extraneous keyword arguments, using
:rename instead of :renamer silently does nothing.

I don't know which of both names is supposed to be right, thus I don't
include a patch.  

-- 
Matthias Köppe -- http://www.math.uni-magdeburg.de/~mkoeppe