More examples

[Martin Grabmueller]

Hello list,

my second example proposal is available under 

http://www.pintus.de/mgrabmue/guile/examples-0.0.2.tar.gz

I have added two examples for ideas mentioned by Thomas and Rob.

1. A version of the box example, where the procedures are defined in a
   module called (box-module).  This explains how to create modules
   from C.

2. A demonstration of safe (sand-boxed) evaluation.  A script is
   included which evaluates a given Scheme file in a safe environment,
   and two example files are there; one working in the safe
   environment, and one crashing because trying to use an `evil'
   procedure (namely, open-input-file).

Feel invited to have a look and let me know if the examples are
useful.

Thanks,
  'martin