One to many relation jet->jets (for jet reclustering)

[clementhelsens]

Hello,

following the discussion we had in the FCCSW technical meeting 12/07/2017, I open an issue to follow up on the implementation of some kind of relations to support one to many relation from a jet to jets. In this context the jet is a large R-jet and the jets are small R jets from re-clustering of the large R-jet clusters. This is particularly useful for analyses heavily using sub-structure in very boosted environment.

Cheers,
Clement