Remove '/' from interface names during import

 * From now on you are allowed to import 'lib' or 'lib.iface', though
   the old method of 'lib/iface' should still work.
Improved the behavior of shlib.doc().

 * Understands finding documentation for a lib vs an procedure.

 * A list of subroutines is automatically produced (might not be
   terribly useful for final MarkDown on GitHub)

 * Whole thing may need to be revisited once we have some real level of
   documentation accessible.