Multiple input files to the service (separated from RE: idpv3 first look)

[Rod Widdowson]

[This seemed to get lost, so resending]

> What's the "filter manager", is that the to-be-written Function passed
> to the ReloadableSpringService to assemble the AttributeFilterImpl from
> the ApplicationContext ?

It's just what I meant to encompass the entirety comprising filter-api,
filter-impl, filter-spring & the configuration fragment in services.xml
 
> I
> think the javadoc for AttributeFilterPolicyGroupParser should be
> updated because it seems to date from when we had an
> AttributerFilterService, 

It was probably a straight port from the V2.  I'll fix that today.

> We got rid of the AttributeFilterService and AttributeResolverService,
> but to support multiple configuration files I think we'll need that
> functionality back, 

Not really.  Or perhaps more accurately we already did when we introduced
the concepts of ServiceableComponent and the ReloadableSping service.  All
that we are doing is moving the responsibility for the creation of the
singleton ServiceableComponent from inside the parsers.  

I'm on a long flight today so I'm intending finishing this off today so it
should get into svn tomorrow am.  AttributeFilter and AttributeResolver will
be easy.  MetadataProvider will be a slightly more challenging.  I do not
propose making it possible to spread legacy relyingparty across multiple
files.  I'll need to see how the non-custom services are handled before I
can work out exactly what we do about them but I suspect that they work will
be a no-op.

Rod