[m-dev.] For review: improve undefined pred/symbol error message

[Thomas Charles CONWAY]

Fergus Henderson, you write:
> The bug is that you need to keep track of not only modules that
> have been imported, but also of modules that have been "used"
> with a `use_module' declaration.

How about include_module - I couldn't find any mention of it in the
notes/module_system.html file?

-- 
Thomas Conway <conway at cs.mu.oz.au>
Nail here [] for new monitor.  )O+