eval, default-imports, and unexpected behavior

[Diego]

I was looking into ways to implement a 'clean' r5rs or r7rs environment in the 
csi repl through csi options, and noticed that by default `eval-handler` from 
chicken.eval imports `default-imports` and `default-syntax-imports`

This has at least two consequences:

a) the following lines that do these imports in csi.scm are superfluous 
(removing them doesn't seem to change csi's behavior, since csi depends on eval 
and therefore eval-handler):

  (eval `(import-for-syntax ,@default-syntax-imports))
  (eval `(import ,@default-imports))

b) You can get what is in my opinion unexpected behavior, for example running 
the following interpreted or compiled code works (but shouldn't):

  (module hey ()
    (import scheme)
    (eval '(print 'hey)))

Is this expected, or should this be reworked somewhat?

As a side note, this also might make it slightly harder to have a more minimal 
environment in the repl (e.g. one that doesn't include chicken.base, towards my 
previously stated goals) but maybe that's just a matter of playing with the 
eval-handler parameter...

- Diego