CLOUDSTACK-5839 : return canEnableIndividualService in listNetworkServiceProvidersResponse
CLOUDSTACK-5733: UI > Virtual Routers > group by zone/pod/cluster: fix a bug that "Total of Virtual Routers" in first row is blank.
CLOUDSTACK-5733: UI > Virtual Routers > group by zone/pod/cluster > remove redundant code.
CLOUDSTACK-5839: fixed xml serializer to process collection field when its elements are of String type