bs2ddist and bsdz histos.
Fix names on norm_belows; turn off fits to deltaphi.
svdz (vs. delta_phi) histos.
"delta_phi" -> "dphi".
When choosing pairs of vertices, consider dz distribution too.
svdz_all_v_dphi ; throw one random number per pair.
Two-step operation.
Set bs2ddist correctly when reading from text file; wrep flag; throw random for dphi, dz separately; give up on edges of (dz) distribution.
s/worep//g.
wrep flag.