Match to both pileup and hard scatter truth jets to find PVz

In !500 (merged) I added matching to truth jets, and saved the truth jet vertex z position when I did. The problem was that I only matched to the pileup truth jets. Here I'm adding hard scatter truth jets to the matching as well (which turns out to be most of the jets in the ttbar sample I'm testing on).

I also added the ability for the jet matching algorithm to take in multiple source jet collections, and to give priority to higher pt jets within a cone, which should be more robust when the jet collections overlap.

Closes #86 (closed).