AP for Lb2etacpk (etac2ppbar & KsKpi) 25c1-c4 data

Analysis Production for Lb2etacpk (etac2ppbar & KsKpi) 25c1-c4 data, without momentum scale calibration.

supersedes !4180 (closed)

Selection:

ipchi2>9 for p/K from Lb and ppbar/Kpi from etac,

ipchi2<16, vchi2<25 for Lb

fdchi2>25, vdz>1.5mm, dls>3 for etac

doca<0.25 between long tracks