Remove internal srfi's

[Geert Janssens]

On Monday 5 April 2010, Derek Atkins wrote:
> John Ralls <jralls at ceridwen.us> writes:
> > I think they can too. The problem is that we officially support guile
> > 1.6.0., and I wasn't able to get that to build so I couldn't check that
> > the gnucash srfis aren't pulled in. If we update the minimum guile
> > version to 1.6.7, we can very safely remove the srfis.
> 
> I think it's safe to require guile >= 1.6.7
> 
> > Regards,
> > John Ralls
> 
> -derek
> 
Done in r18995.

Geert