Update PrCloneKiller

Update PrCloneKiller

• uses the difference in slopes between the reference tracks and the declonable tracks to speed up the clone identification.

This does not 100% preserve the old values, but the differences are usually below 0.01%, except for the clone killing step between forward tracks and match tracks. Here the old algorithm identifies two tracks as clones if they share their x hits in the SciFi, (but none of the stereo hits), have a very small momentum difference, but share no hits in the Velo. The updated clone killer does not treat them as clones, leading to a difference of about 0.05% in the number of tracks.

Needs !4453 (merged) and LHCb!5168 (merged)