Fixes from Marian: AliTRDseedV1.cxx - adding correction for pad crossing 0 with effective factor for incoplete model AliTRDtrackerV1.cxx - adding chi2 to the streamer AliTRDrecoParam.h AliTRDrecoParam.cxx AliTRDtrackerV1.cxx - parameterised chi2 cut /tracklet to track AliTRDseedV1.cxx - increase error estimate for crossing tracklets -taking incount unisochronity, and crosscorelation of errors