changes to notifications yang models break external Netconf devices

the notifications.yang, nc-notifications.yang and ietf-netconf-notifications.yang modules in ODL do import by revision (unlike the standard IETF models).

this breaks external NETCONF servers which support these models unless they also support the same revisions of ietf-inet-types.yang and ietf-yang-types.yang as referenced in those ODL models (2010-09-24).

Is there a reason for the ODL models to import by revision? The IETF versions don't.