group memberships from two sources

[David Bantz]

This seems to work to provide the literal values of AD's memberOf attribute:
...
<resolver:AttributeDefinition id="ADMemberOf" xsi:type="Simple" xmlns="urn:mace:shibboleth:2.0:resolver:ad" sourceAttributeID="memberOf">
	<resolver:Dependency ref="uaADLDAP" />
	<resolver:AttributeEncoder xsi:type="SAML2String" xmlns="urn:mace:shibboleth:2.0:attribute:encoder" name="urn:oid:1.2.840.113556.1.2.102" friendlyName="ADmemberOf" />
</resolver:AttributeDefinition>