Function use in the IdP

[Brent Putman]

On 11/20/14 8:39 AM, Rod Widdowson wrote:
>>
> I added this as discussed but I just realized that there is a fault in my
> reasoning.  We have a plug point, and we have a pluggable function, but we
> have not way of doing the plugging because the SignatureValidationFilter is
> added via the custom schema.

Ah, yes, forgot about the schema.   The filter defaults in our Basic-
impl of that function, but if we want to allow customization obviously
we need to add a slot on the custom schema and parser.  There may be
some other things too that we need to add on signature filter.  I
vaguely recall some other changes there that may not have been reflected
in the schema.  I'll look later today.