heat engine : Compare runtime resolved resource snippets on update
heat engine : Compare runtime resolved resource snippets on update

We need to compare the runtime resolved resource snippet, since that
is what we get back from self.parsed_template.  If we don't do this,
then we get a false positive when a Ref to a parameter which gets
updated (e.g AWS::StackId) is used in the resource properties.

ref bug 1131666

Change-Id: Ib488c43b9eca998a7a82b7571097f5bb69ef946c

dims/heat,NeCTAR-RC/heat,dims/heat,JioCloud/heat,rickerc/heat_audit,redhat-openstack/heat,cryptickp/heat,dragorosson/heat,redhat-openstack/heat,ntt-sic/heat,rh-s/heat,jasondunsmore/heat,rdo-management/heat,NeCTAR-RC/heat,citrix-openstack-build/heat,jasondunsmore/heat,gonzolino/heat,takeshineshiro/heat,ntt-sic/heat,openstack/heat,noironetworks/heat,JioCloud/heat,rickerc/heat_audit,srznew/heat,pshchelo/heat,rdo-management/heat,steveb/heat,citrix-openstack-build/heat,takeshineshiro/heat,varunarya10/heat,dragorosson/heat,cwolferh/heat-scratch,maestro-hybrid-cloud/heat,miguelgrinberg/heat,maestro-hybrid-cloud/heat,rh-s/heat,steveb/heat,miguelgrinberg/heat,Triv90/Heat,pshchelo/heat,noironetworks/heat,openstack/heat,cryptickp/heat,pratikmallya/heat,Triv90/Heat,pratikmallya/heat,varunarya10/heat,srznew/heat,cwolferh/heat-scratch,gonzolino/heat,Triv90/Heat