Finalizing TrustEngine config

[Rod Widdowson]

> The common factor seems to be the default list, independent of what
> they're being loaded into, because that part is different in each case.
 
> Basically this:

[Right]

> It would depend on what needs it. Right now, I use it in
> relying-party-system.xml, and my hope was to move the trust engine config
> there as well.
> 
> If the custom parser you mean is the RelyingParty one, that means we'd
> need it in the profile-defaults config. Is that it?

I mean the parsers for things like

	<security:TrustEngine id="MyTrustEngine"
xsi:type="security:StaticExplicitKeySignature">
		<security:Credential id="IdPCredential"
xsi:type="security:X509Filesystem">
	
<security:Certificate>${DIR}/filter/switch.pem</security:Certificate>
		</security:Credential>
	</security:TrustEngine>

The constructor for the trust engine (in this case
org.opensaml.xmlsec.signature.support.impl.ExplicitKeySignatureTrustEngine)
needs a KeyInfoCredentialResolver which is instantiated as "new
org.opensaml.xmlsec.keyinfo.impl.BasicProviderKeyInfoCredentialResolver
(that list)" 

In V2 (and currently in V3) that is created on the fly *in the parser* which
is completely against our desire to leave defaulting in the objects or the
XML.  It might well be that a centrally defined list is not what we need.

R