need mechanism to get ODL version

We need a mechanism to get the ODL version from:
1) karaf CLI
2) REST (or RESTCONF)
3) NETCONF/YANG

I'm not sure where this should live - odlparent, controller (does that still exist as a project post-Lithium), or md-sal (but then you need to have md-sal to make this work - though does a controller with no md-sal make sense?)