New B0 -> 4pi phase space CP model: LHCBGAUSS-1614.EvtGenExtras

Jeremy Peter Dalsenorequested to merge
LHCBGAUSS-1614.EvtGenExtras into Sim09

See Jira ticket for more detailed description, LHCBGAUSS-1614

To also propagate to master and Sim09-upgrade branches.

Merge request reports