B2OC: add new DDKpi sprucing lines
Add new lines for B0 -> D0D0Kpi, for D0(Kpi)D0(K3pi) and D0(K3pi)D0(K3pi).
Update existing D0(Kpi)D0(Kpi) line to use the full kinematically allowed range for the Kpi pair, not just a narrow Kst(892) mass window.
Edited by Alessandro Bertolin